0000893818 2026-01-01 2026-06-30 0000893818 cik0000893818:C000074119Member 2026-01-01 2026-06-30 0000893818 cik0000893818:C000011980Member 2026-01-01 2026-06-30 0000893818 cik0000893818:C000074117Member 2026-01-01 2026-06-30 0000893818 cik0000893818:C000244481Member 2026-01-01 2026-06-30 0000893818 cik0000893818:C000102141Member 2026-01-01 2026-06-30 0000893818 cik0000893818:C000102140Member 2026-01-01 2026-06-30 0000893818 cik0000893818:C000102142Member 2026-01-01 2026-06-30 0000893818 cik0000893818:C000098724Member 2026-01-01 2026-06-30 0000893818 cik0000893818:C000098723Member 2026-01-01 2026-06-30 0000893818 cik0000893818:C000098725Member 2026-01-01 2026-06-30 0000893818 cik0000893818:C000117726Member 2026-01-01 2026-06-30 0000893818 cik0000893818:C000117728Member 2026-01-01 2026-06-30 0000893818 cik0000893818:C000117725Member 2026-01-01 2026-06-30 0000893818 cik0000893818:C000201951Member 2026-01-01 2026-06-30 0000893818 cik0000893818:C000212062Member 2026-01-01 2026-06-30 0000893818 cik0000893818:C000011979Member 2026-01-01 2026-06-30 0000893818 cik0000893818:C000099167Member 2026-01-01 2026-06-30 0000893818 cik0000893818:C000099166Member 2026-01-01 2026-06-30 0000893818 cik0000893818:C000201953Member 2026-01-01 2026-06-30 0000893818 cik0000893818:C000011974Member 2026-01-01 2026-06-30 0000893818 cik0000893818:C000074119Member 2026-06-30 0000893818 cik0000893818:C000011980Member 2026-06-30 0000893818 cik0000893818:C000074117Member 2026-06-30 0000893818 cik0000893818:C000244481Member 2026-06-30 0000893818 cik0000893818:C000102141Member 2026-06-30 0000893818 cik0000893818:C000102140Member 2026-06-30 0000893818 cik0000893818:C000102142Member 2026-06-30 0000893818 cik0000893818:C000098724Member 2026-06-30 0000893818 cik0000893818:C000098723Member 2026-06-30 0000893818 cik0000893818:C000098725Member 2026-06-30 0000893818 cik0000893818:C000117726Member 2026-06-30 0000893818 cik0000893818:C000117728Member 2026-06-30 0000893818 cik0000893818:C000117725Member 2026-06-30 0000893818 cik0000893818:C000201951Member 2026-06-30 0000893818 cik0000893818:C000212062Member 2026-06-30 0000893818 cik0000893818:C000011979Member 2026-06-30 0000893818 cik0000893818:C000099167Member 2026-06-30 0000893818 cik0000893818:C000099166Member 2026-06-30 0000893818 cik0000893818:C000201953Member 2026-06-30 0000893818 cik0000893818:C000011974Member 2026-06-30 iso4217:USD pure cik0000893818:Holding N-CSRS false 0000893818 N-1A BlackRock Funds III 2026-06-30 BlackRock Cash Funds: Institutional SL Agency Shares BISXX This semi-annual shareholder report contains important information about BlackRock Cash Funds: Institutional (the “Fund”) for the period of January 1, 2026 to June 30, 2026. semi-annual shareholder report The Fund invests all of its assets in the Money Market Master Portfolio (the “Master Portfolio”), a series of Master Investment Portfolio. You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (888) 204-3956. blackrock.com/fundreports (888) 204-3956 <div style="margin-top: 0; margin-right: 0; margin-bottom: -0.18pt; margin-left: 0; font-family: 'Arial'; font-kerning: none; font-weight: bold; font-size: 10pt; color: rgb(0, 0, 0);"><div style="font-weight:bolder;display:inline;">What were the </div> <div style="font-weight:bolder;display:inline;">Fund</div> <div style="font-weight:bolder;display:inline;"> costs for the </div> <div style="font-weight:bolder;display:inline;">last six months</div> <div style="font-weight:bolder;display:inline;">?</div> </div> <div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-family: 'Arial'; font-size: 9pt; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none;">(based on a hypothetical $10,000 investment)</div> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); vertical-align: bottom; padding: 2pt 0px; text-align: left;"><div style="font-weight:bolder;display:inline;">Class name</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs of a $10,000<br/>investment</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs paid as a percentage of a<br/>$10,000 investment</div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; font-size: 8pt; line-height: 10pt; text-align: left;">SL Agency Shares</td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>5<div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; letter-spacing: 0px; top: 0px;display:inline;">(a)</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;">0.09<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(a)(b)</div></td></tr></table> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid; font-family: Arial; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding: 1.6pt 6pt 0px 0px; width: initial; vertical-align: top; text-indent: 0px; white-space: nowrap;"><div style="margin: 0px; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: Arial; font-style: normal; font-size: 7pt; line-height: 11pt; text-align: justify; vertical-align: top; padding: 0px; white-space: nowrap;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; white-space: nowrap;display:inline;">(a)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; text-indent: 0; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. </div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid; font-family: Arial; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding: 0px 6pt 0px 0px; width: initial; vertical-align: top; text-indent: 0px; white-space: nowrap;"><div style="margin: 0px; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: Arial; font-style: normal; font-size: 7pt; line-height: 12pt; text-align: justify; vertical-align: top; padding: 0px; white-space: nowrap;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; white-space: nowrap;display:inline;">(b)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Annualized.</div></td></tr></table> 5 0.0009 Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. <table style="text-align:start; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse; margin-top: 0;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; background-color: rgb(255, 206, 0); border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; color: rgb(0, 0, 0); vertical-align: bottom; width: auto; font-size: 10pt; line-height: normal; text-align: left; text-indent: 0px; letter-spacing: normal; text-transform: none; font-kerning: none; padding: 2pt 0px 1.5pt; margin-top: 0px; margin-bottom: 0px;"><div style="font-weight:bolder;display:inline;">Key Fund statistics</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Net Assets</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>107,880,346,482</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Number of Portfolio Holdings</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;">1</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 0; text-indent: 0;"><div style="font-weight:bolder;display:inline;width:100%;">Current seven-day yields as of June 30, 2026 (The 7-Day SEC Yield may differ from the 7-Day Yield shown due to<br/>the fact that the 7-Day SEC Yield excludes distributed capital gains.)</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"> </td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 12pt; text-indent: -6pt;">7-Day SEC Yield</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;">3.82<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 12pt; text-indent: -6pt;">7-Day Yield</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt;">3.82<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div></td></tr></table> 107880346482 1 Past performance is not an indication of future results. Visit blackrock.com for more recent yield information. BlackRock Cash Funds: Treasury Institutional Shares BRIXX This semi-annual shareholder report contains important information about BlackRock Cash Funds: Treasury (the “Fund”) for the period of January 1, 2026 to June 30, 2026. semi-annual shareholder report The Fund invests all of its assets in the Treasury Money Market Master Portfolio (the “Master Portfolio”), a series of Master Investment Portfolio.You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (888) 204-3956. blackrock.com/fundreports (888) 204-3956 <div style="margin-top: 0; margin-right: 0; margin-bottom: -0.18pt; margin-left: 0; font-family: 'Arial'; font-kerning: none; font-weight: bold; font-size: 10pt; color: rgb(0, 0, 0);"><div style="font-weight:bolder;display:inline;">What were the </div> <div style="font-weight:bolder;display:inline;">Fund</div> <div style="font-weight:bolder;display:inline;"> costs for the </div> <div style="font-weight:bolder;display:inline;">last six months</div> <div style="font-weight:bolder;display:inline;">?</div> </div> <div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-family: 'Arial'; font-size: 9pt; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none;">(based on a hypothetical $10,000 investment)</div> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); vertical-align: bottom; padding: 2pt 0px; text-align: left;"><div style="font-weight:bolder;display:inline;">Class name</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs of a $10,000<br/>investment</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs paid as a percentage of a<br/>$10,000 investment</div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; font-size: 8pt; line-height: 10pt; text-align: left;">Institutional Shares</td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>6<div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; letter-spacing: 0px; top: 0px;display:inline;">(a)</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;">0.12<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(a)(b)</div></td></tr></table> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid; font-family: Arial; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding: 1.6pt 6pt 0px 0px; width: initial; vertical-align: top; text-indent: 0px; white-space: nowrap;"><div style="margin: 0px; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: Arial; font-style: normal; font-size: 7pt; line-height: 11pt; text-align: justify; vertical-align: top; padding: 0px; white-space: nowrap;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; white-space: nowrap;display:inline;">(a)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; text-indent: 0; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. </div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid; font-family: Arial; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding: 0px 6pt 0px 0px; width: initial; vertical-align: top; text-indent: 0px; white-space: nowrap;"><div style="margin: 0px; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: Arial; font-style: normal; font-size: 7pt; line-height: 11pt; text-align: justify; vertical-align: top; padding: 0px; white-space: nowrap;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; white-space: nowrap;display:inline;">(b)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Annualized.</div></td></tr></table> 6 0.0012 Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. <table style="text-align:start; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse; margin-top: 0;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; background-color: rgb(255, 206, 0); border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; color: rgb(0, 0, 0); vertical-align: bottom; width: auto; font-size: 10pt; line-height: normal; text-align: left; text-indent: 0px; letter-spacing: normal; text-transform: none; font-kerning: none; padding: 2pt 0px 1.5pt; margin-top: 0px; margin-bottom: 0px;"><div style="font-weight:bolder;display:inline;">Key Fund statistics</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Net Assets</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>20,632,269,684</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Number of Portfolio Holdings</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;">1</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 0; text-indent: 0;"><div style="font-weight:bolder;display:inline;width:100%;">Current seven-day yields as of June 30, 2026 (The 7-Day SEC Yield may differ from the 7-Day Yield shown due to<br/>the fact that the 7-Day SEC Yield excludes distributed capital gains.)</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"> </td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 12pt; text-indent: -6pt;">7-Day SEC Yield</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;">3.59<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 12pt; text-indent: -6pt;">7-Day Yield</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt;">3.59<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div></td></tr></table> 20632269684 1 Past performance is not an indication of future results. Visit blackrock.com for more recent yield information. BlackRock Cash Funds: Treasury SL Agency Shares XTSLA This semi-annual shareholder report contains important information about BlackRock Cash Funds: Treasury (the “Fund”) for the period of January 1, 2026 to June 30, 2026. semi-annual shareholder report The Fund invests all of its assets in the Treasury Money Market Master Portfolio (the “Master Portfolio”), a series of Master Investment Portfolio. You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (888) 204-3956. blackrock.com/fundreports (888) 204-3956 <div style="margin-top: 0; margin-right: 0; margin-bottom: -0.18pt; margin-left: 0; font-family: 'Arial'; font-kerning: none; font-weight: bold; font-size: 10pt; color: rgb(0, 0, 0);"><div style="font-weight:bolder;display:inline;">What were the </div> <div style="font-weight:bolder;display:inline;">Fund</div> <div style="font-weight:bolder;display:inline;"> costs for the </div> <div style="font-weight:bolder;display:inline;">last six months</div> <div style="font-weight:bolder;display:inline;">?</div> </div> <div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-family: 'Arial'; font-size: 9pt; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none;">(based on a hypothetical $10,000 investment)</div> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); vertical-align: bottom; padding: 2pt 0px; text-align: left;"><div style="font-weight:bolder;display:inline;">Class name</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs of a $10,000<br/>investment</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs paid as a percentage of a<br/>$10,000 investment</div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; font-size: 8pt; line-height: 10pt; text-align: left;">SL Agency Shares</td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>5<div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; letter-spacing: 0px; top: 0px;display:inline;">(a)</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;">0.09<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(a)(b)</div></td></tr></table> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid; font-family: Arial; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding: 1.6pt 6pt 0px 0px; width: initial; vertical-align: top; text-indent: 0px; white-space: nowrap;"><div style="margin: 0px; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: Arial; font-style: normal; font-size: 7pt; line-height: 11pt; text-align: justify; vertical-align: top; padding: 0px; white-space: nowrap;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; white-space: nowrap;display:inline;">(a)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; text-indent: 0; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. </div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid; font-family: Arial; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding: 0px 6pt 0px 0px; width: initial; vertical-align: top; text-indent: 0px; white-space: nowrap;"><div style="margin: 0px; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: Arial; font-style: normal; font-size: 7pt; line-height: 11pt; text-align: justify; vertical-align: top; padding: 0px; white-space: nowrap;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; white-space: nowrap;display:inline;">(b)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Annualized.</div></td></tr></table> 5 0.0009 Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. <table style="text-align:start; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse; margin-top: 0;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; background-color: rgb(255, 206, 0); border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; color: rgb(0, 0, 0); vertical-align: bottom; width: auto; font-size: 10pt; line-height: normal; text-align: left; text-indent: 0px; letter-spacing: normal; text-transform: none; font-kerning: none; padding: 2pt 0px 1.5pt; margin-top: 0px; margin-bottom: 0px;"><div style="font-weight:bolder;display:inline;">Key Fund statistics</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Net Assets</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>20,632,269,684</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Number of Portfolio Holdings</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;">1</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 0; text-indent: 0;"><div style="font-weight:bolder;display:inline;width:100%;">Current seven-day yields as of June 30, 2026 (The 7-Day SEC Yield may differ from the 7-Day Yield shown due to<br/>the fact that the 7-Day SEC Yield excludes distributed capital gains.)</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"> </td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 12pt; text-indent: -6pt;">7-Day SEC Yield</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;">3.62<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 12pt; text-indent: -6pt;">7-Day Yield</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt;">3.62<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div></td></tr></table> 20632269684 1 Past performance is not an indication of future results. Visit blackrock.com for more recent yield information. BlackRock Diversified Equity Alpha Fund Institutional Shares BDVEX This semi-annual shareholder report contains important information about BlackRock Diversified Equity Alpha Fund (the “Fund”) (formerly known as BlackRock Diversified Equity Fund) for the period of January 1, 2026 to June 30, 2026. semi-annual shareholder report The Fund invests all of its assets in the Diversified Equity Alpha Master Portfolio (the “Master Portfolio”) (formerly known as Diversified Equity Master Portfolio), a series of Master Investment Portfolio. You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 537-4942. blackrock.com/fundreports (800)537-4942 <div style="margin-top: 0; margin-right: 0; margin-bottom: -0.18pt; margin-left: 0; font-family: 'Arial'; font-kerning: none; font-weight: bold; font-size: 10pt; color: rgb(0, 0, 0);"><div style="font-weight:bolder;display:inline;">What were the </div> <div style="font-weight:bolder;display:inline;">Fund</div> <div style="font-weight:bolder;display:inline;"> costs for the </div> <div style="font-weight:bolder;display:inline;">last six months</div> <div style="font-weight:bolder;display:inline;">?</div> </div> <div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-family: 'Arial'; font-size: 9pt; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none;">(based on a hypothetical $10,000 investment)</div> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); vertical-align: bottom; padding: 2pt 0px; text-align: left;"><div style="font-weight:bolder;display:inline;">Class name</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs of a $10,000<br/>investment</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs paid as a percentage of a<br/>$10,000 investment</div></td> </tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; font-size: 8pt; line-height: 10pt; text-align: left;">Institutional Shares</td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>20<div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; letter-spacing: 0px; top: 0px;display:inline;">(a)</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;">0.39<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(a)(b)</div></td> </tr> </table> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid; font-family: Arial; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding: 1.6pt 6pt 0px 0px; width: initial; vertical-align: top; text-indent: 0px; white-space: nowrap;"> <div style="margin: 0px; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: Arial; font-style: normal; font-size: 7pt; line-height: 11pt; text-align: justify; vertical-align: top; padding: 0px; white-space: nowrap;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; white-space: nowrap;display:inline;">(a)</div></div> </td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; text-indent: 0; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: 100%;"> <div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. </div> </td> </tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding-top: 0; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: initial; vertical-align: top; text-indent: 0;"> <div style="margin-top: 0;margin-right: 0;margin-bottom: 0;margin-left: 0;font-weight: normal;color: rgb(0, 0, 0);font-kerning: none;font-family: 'Arial';font-style: normal;font-size: 7pt;line-height: 11pt;text-align: justify;vertical-align: top;padding-top: 0;padding-right: 0;padding-bottom: 0;padding-left: 0;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(b)</div></div> </td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0; width: 100%;"> <div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Annualized.</div> </td> </tr> </table> 20 0.0039 Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. <table style="text-align:start; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse; margin-top: 0;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; background-color: rgb(255, 206, 0); border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; color: rgb(0, 0, 0); vertical-align: bottom; width: auto; font-size: 10pt; line-height: normal; text-align: left; text-indent: 0px; letter-spacing: normal; text-transform: none; font-kerning: none; padding: 2pt 0px 1.5pt; margin-top: 0px; margin-bottom: 0px;"><div style="font-weight:bolder;display:inline;">Key Fund statistics</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"></td> </tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Net Assets</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>1,313,581,420</td> </tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Number of Portfolio Holdings</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;">1</td> </tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt; text-indent: -6pt;">Portfolio Turnover Rate of the Master Portfolio</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt;">51<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div></td> </tr> </table> 1313581420 1 0.51 iShares MSCI Total International Index Fund Institutional Shares BDOIX This semi-annual shareholder report contains important information about iShares MSCI Total International Index Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026. semi-annual shareholder report The Fund invests all of its assets in the Total International ex U.S. Index Master Portfolio (the “Master Portfolio”), a series of Master Investment Portfolio. You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441-7762. blackrock.com/fundreports (800) 441-7762 <div style="margin-top: 0; margin-right: 0; margin-bottom: -0.18pt; margin-left: 0; font-family: 'Arial'; font-kerning: none; font-weight: bold; font-size: 10pt; color: rgb(0, 0, 0);"><div style="font-weight:bolder;display:inline;">What were the </div> <div style="font-weight:bolder;display:inline;">Fund</div> <div style="font-weight:bolder;display:inline;"> costs for the </div> <div style="font-weight:bolder;display:inline;">last six months</div> <div style="font-weight:bolder;display:inline;">?</div> </div> <div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-family: 'Arial'; font-size: 9pt; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none;">(based on a hypothetical $10,000 investment)</div> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); vertical-align: bottom; padding: 2pt 0px; text-align: left;"><div style="font-weight:bolder;display:inline;">Class name</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs of a $10,000<br/>investment</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs paid as a percentage of a<br/>$10,000 investment</div></td> </tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; font-size: 8pt; line-height: 10pt; text-align: left;">Institutional Shares</td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>7<div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; letter-spacing: 0px; top: 0px;display:inline;">(a)</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;">0.13<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(a)(b)</div></td> </tr> </table> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid; font-family: Arial; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding: 1.6pt 6pt 0px 0px; width: initial; vertical-align: top; text-indent: 0px; white-space: nowrap;"> <div style="margin: 0px; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: Arial; font-style: normal; font-size: 7pt; line-height: 11pt; text-align: justify; vertical-align: top; padding: 0px; white-space: nowrap;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; white-space: nowrap;display:inline;">(a)</div></div> </td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; text-indent: 0; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: 100%;"> <div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. </div> </td> </tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding-top: 0; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: initial; vertical-align: top; text-indent: 0;"> <div style="margin-top: 0;margin-right: 0;margin-bottom: 0;margin-left: 0;font-weight: normal;color: rgb(0, 0, 0);font-kerning: none;font-family: 'Arial';font-style: normal;font-size: 7pt;line-height: 11pt;text-align: justify;vertical-align: top;padding-top: 0;padding-right: 0;padding-bottom: 0;padding-left: 0;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(b)</div></div> </td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0; width: 100%;"> <div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Annualized.</div> </td> </tr> </table> 7 0.0013 Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. <table style="text-align:start; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse; margin-top: 0;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; background-color: rgb(255, 206, 0); border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; color: rgb(0, 0, 0); vertical-align: bottom; width: auto; font-size: 10pt; line-height: normal; text-align: left; text-indent: 0px; letter-spacing: normal; text-transform: none; font-kerning: none; padding: 2pt 0px 1.5pt; margin-top: 0px; margin-bottom: 0px;"><div style="font-weight:bolder;display:inline;">Key Fund statistics</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"></td> </tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Net Assets</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>2,515,814,503</td> </tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Number of Portfolio Holdings</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;">1</td> </tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt; text-indent: -6pt;">Portfolio Turnover Rate of the Master Portfolio</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt;">2<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div></td> </tr> </table> 2515814503 1 0.02 iShares MSCI Total International Index Fund Investor A Shares BDOAX This semi-annual shareholder report contains important information about iShares MSCI Total International Index Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026. semi-annual shareholder report The Fund invests all of its assets in the Total International ex U.S. Index Master Portfolio (the “Master Portfolio”), a series of Master Investment Portfolio. You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441-7762. blackrock.com/fundreports (800) 441-7762 <div style="margin-top: 0; margin-right: 0; margin-bottom: -0.18pt; margin-left: 0; font-family: 'Arial'; font-kerning: none; font-weight: bold; font-size: 10pt; color: rgb(0, 0, 0);"><div style="font-weight:bolder;display:inline;">What were the </div> <div style="font-weight:bolder;display:inline;">Fund</div> <div style="font-weight:bolder;display:inline;"> costs for the </div> <div style="font-weight:bolder;display:inline;">last six months</div> <div style="font-weight:bolder;display:inline;">?</div> </div> <div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-family: 'Arial'; font-size: 9pt; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none;">(based on a hypothetical $10,000 investment)</div> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); vertical-align: bottom; padding: 2pt 0px; text-align: left;"><div style="font-weight:bolder;display:inline;">Class name</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs of a $10,000<br/>investment</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs paid as a percentage of a<br/>$10,000 investment</div></td> </tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; font-size: 8pt; line-height: 10pt; text-align: left;">Investor A Shares</td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>21<div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; letter-spacing: 0px; top: 0px;display:inline;">(a)</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;">0.39<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(a)(b)</div></td> </tr> </table> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid; font-family: Arial; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding: 1.6pt 6pt 0px 0px; width: initial; vertical-align: top; text-indent: 0px; white-space: nowrap;"> <div style="margin: 0px; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: Arial; font-style: normal; font-size: 7pt; line-height: 11pt; text-align: justify; vertical-align: top; padding: 0px; white-space: nowrap;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; white-space: nowrap;display:inline;">(a)</div></div> </td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; text-indent: 0; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: 100%;"> <div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. </div> </td> </tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding-top: 0; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: initial; vertical-align: top; text-indent: 0;"> <div style="margin-top: 0;margin-right: 0;margin-bottom: 0;margin-left: 0;font-weight: normal;color: rgb(0, 0, 0);font-kerning: none;font-family: 'Arial';font-style: normal;font-size: 7pt;line-height: 11pt;text-align: justify;vertical-align: top;padding-top: 0;padding-right: 0;padding-bottom: 0;padding-left: 0;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(b)</div></div> </td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0; width: 100%;"> <div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Annualized.</div> </td> </tr> </table> 21 0.0039 Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. <table style="text-align:start; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse; margin-top: 0;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; background-color: rgb(255, 206, 0); border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; color: rgb(0, 0, 0); vertical-align: bottom; width: auto; font-size: 10pt; line-height: normal; text-align: left; text-indent: 0px; letter-spacing: normal; text-transform: none; font-kerning: none; padding: 2pt 0px 1.5pt; margin-top: 0px; margin-bottom: 0px;"><div style="font-weight:bolder;display:inline;">Key Fund statistics</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"></td> </tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Net Assets</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>2,515,814,503</td> </tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Number of Portfolio Holdings</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;">1</td> </tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt; text-indent: -6pt;">Portfolio Turnover Rate of the Master Portfolio</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt;">2<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div></td> </tr> </table> 2515814503 1 0.02 iShares MSCI Total International Index Fund Class K Shares BDOKX This semi-annual shareholder report contains important information about iShares MSCI Total International Index Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026. semi-annual shareholder report The Fund invests all of its assets in the Total International ex U.S. Index Master Portfolio (the “Master Portfolio”), a series of Master Investment Portfolio. You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441-7762. blackrock.com/fundreports (800) 441-7762 <div style="font-family: 'Arial'; font-size: 9pt; font-weight: normal; color: rgb(0, 0, 0); margin-bottom: 5pt;"> </div> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); vertical-align: bottom; padding: 2pt 0px; text-align: left;"><div style="font-weight:bolder;display:inline;">Class name</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs of a $10,000<br/>investment</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs paid as a percentage of a<br/>$10,000 investment</div></td> </tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; font-size: 8pt; line-height: 10pt; text-align: left;">Class K Shares</td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>4<div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; letter-spacing: 0px; top: 0px;display:inline;">(a)</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;">0.08<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(a)(b)</div></td> </tr> </table> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid; font-family: Arial; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding: 1.6pt 6pt 0px 0px; width: initial; vertical-align: top; text-indent: 0px; white-space: nowrap;"> <div style="margin: 0px; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: Arial; font-style: normal; font-size: 7pt; line-height: 11pt; text-align: justify; vertical-align: top; padding: 0px; white-space: nowrap;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; white-space: nowrap;display:inline;">(a)</div></div> </td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; text-indent: 0; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: 100%;"> <div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. </div> </td> </tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding-top: 0; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: initial; vertical-align: top; text-indent: 0;"> <div style="margin-top: 0;margin-right: 0;margin-bottom: 0;margin-left: 0;font-weight: normal;color: rgb(0, 0, 0);font-kerning: none;font-family: 'Arial';font-style: normal;font-size: 7pt;line-height: 11pt;text-align: justify;vertical-align: top;padding-top: 0;padding-right: 0;padding-bottom: 0;padding-left: 0;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(b)</div></div> </td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0; width: 100%;"> <div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Annualized.</div> </td> </tr> </table> 4 0.0008 Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. <table style="text-align:start; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse; margin-top: 0;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; background-color: rgb(255, 206, 0); border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; color: rgb(0, 0, 0); vertical-align: bottom; width: auto; font-size: 10pt; line-height: normal; text-align: left; text-indent: 0px; letter-spacing: normal; text-transform: none; font-kerning: none; padding: 2pt 0px 1.5pt; margin-top: 0px; margin-bottom: 0px;"><div style="font-weight:bolder;display:inline;">Key Fund statistics</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"></td> </tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Net Assets</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>2,515,814,503</td> </tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Number of Portfolio Holdings</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;">1</td> </tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt; text-indent: -6pt;">Portfolio Turnover Rate of the Master Portfolio</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt;">2<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div></td> </tr> </table> 2515814503 1 0.02 iShares Russell 1000 Large-Cap Index Fund Institutional Shares BRGNX This semi-annual shareholder report contains important information about iShares Russell 1000 Large-Cap Index Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026. semi-annual shareholder report The Fund invests all of its assets in the Large Cap Index Master Portfolio (the “Master Portfolio”), a series of Master Investment Portfolio. You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441-7762. blackrock.com/fundreports (800) 441-7762 <div style="margin-top: 0; margin-right: 0; margin-bottom: -0.18pt; margin-left: 0; font-family: 'Arial'; font-kerning: none; font-weight: bold; font-size: 10pt; color: rgb(0, 0, 0);"><div style="font-weight:bolder;display:inline;">What were the </div> <div style="font-weight:bolder;display:inline;">Fund</div> <div style="font-weight:bolder;display:inline;"> costs for the </div> <div style="font-weight:bolder;display:inline;">last six months</div> <div style="font-weight:bolder;display:inline;">?</div> </div> <div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-family: 'Arial'; font-size: 9pt; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none;">(based on a hypothetical $10,000 investment)</div> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); vertical-align: bottom; padding: 2pt 0px; text-align: left;"><div style="font-weight:bolder;display:inline;">Class name</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs of a $10,000<br/>investment</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs paid as a percentage of a<br/>$10,000 investment</div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; font-size: 8pt; line-height: 10pt; text-align: left;">Institutional Shares</td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>5<div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; letter-spacing: 0px; top: 0px;display:inline;">(a)</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;">0.10<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(a)(b)</div></td></tr></table> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid; font-family: Arial; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding: 1.6pt 6pt 0px 0px; width: initial; vertical-align: top; text-indent: 0px; white-space: nowrap;"><div style="margin: 0px; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: Arial; font-style: normal; font-size: 7pt; line-height: 11pt; text-align: justify; vertical-align: top; padding: 0px; white-space: nowrap;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; white-space: nowrap;display:inline;">(a)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; text-indent: 0; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. </div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding-top: 0; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: initial; vertical-align: top; text-indent: 0;"><div style="margin-top: 0;margin-right: 0;margin-bottom: 0;margin-left: 0;font-weight: normal;color: rgb(0, 0, 0);font-kerning: none;font-family: 'Arial';font-style: normal;font-size: 7pt;line-height: 11pt;text-align: justify;vertical-align: top;padding-top: 0;padding-right: 0;padding-bottom: 0;padding-left: 0;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(b)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Annualized.</div></td></tr></table> 5 0.001 Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. <table style="text-align:start; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse; margin-top: 0;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; background-color: rgb(255, 206, 0); border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; color: rgb(0, 0, 0); vertical-align: bottom; width: auto; font-size: 10pt; line-height: normal; text-align: left; text-indent: 0px; letter-spacing: normal; text-transform: none; font-kerning: none; padding: 2pt 0px 1.5pt; margin-top: 0px; margin-bottom: 0px;"><div style="font-weight:bolder;display:inline;">Key Fund statistics</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Net Assets</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>2,034,134,744</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Number of Portfolio Holdings</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;">1</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt; text-indent: -6pt;">Portfolio Turnover Rate of the Master Portfolio</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt;">8<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div></td></tr></table> 2034134744 1 0.08 iShares Russell 1000 Large-Cap Index Fund Investor A Shares BRGAX This semi-annual shareholder report contains important information about iShares Russell 1000 Large-Cap Index Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026. semi-annual shareholder report The Fund invests all of its assets in the Large Cap Index Master Portfolio (the “Master Portfolio”), a series of Master Investment Portfolio. You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441-7762. blackrock.com/fundreports (800) 441-7762 <div style="margin-top: 0; margin-right: 0; margin-bottom: -0.18pt; margin-left: 0; font-family: 'Arial'; font-kerning: none; font-weight: bold; font-size: 10pt; color: rgb(0, 0, 0);"><div style="font-weight:bolder;display:inline;">What were the </div> <div style="font-weight:bolder;display:inline;">Fund</div> <div style="font-weight:bolder;display:inline;"> costs for the </div> <div style="font-weight:bolder;display:inline;">last six mon<div style="display:inline;">t</div>hs</div> <div style="font-weight:bolder;display:inline;">?</div> </div> <div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-family: 'Arial'; font-size: 9pt; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none;">(based on a hypothetical $10,000 investment)</div> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); vertical-align: bottom; padding: 2pt 0px; text-align: left;"><div style="font-weight:bolder;display:inline;">Class name</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs of a $10,000<br/>investment</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs paid as a percentage of a<br/>$10,000 investment</div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; font-size: 8pt; line-height: 10pt; text-align: left;">Investor A Shares</td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>18<div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; letter-spacing: 0px; top: 0px;display:inline;">(a)</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;">0.35<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(a)(b)</div></td></tr></table> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid; font-family: Arial; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding: 1.6pt 6pt 0px 0px; width: initial; vertical-align: top; text-indent: 0px; white-space: nowrap;"><div style="margin: 0px; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: Arial; font-style: normal; font-size: 7pt; line-height: 11pt; text-align: justify; vertical-align: top; padding: 0px; white-space: nowrap;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; white-space: nowrap;display:inline;">(a)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; text-indent: 0; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. </div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding-top: 0; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: initial; vertical-align: top; text-indent: 0;"><div style="margin-top: 0;margin-right: 0;margin-bottom: 0;margin-left: 0;font-weight: normal;color: rgb(0, 0, 0);font-kerning: none;font-family: 'Arial';font-style: normal;font-size: 7pt;line-height: 11pt;text-align: justify;vertical-align: top;padding-top: 0;padding-right: 0;padding-bottom: 0;padding-left: 0;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(b)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Annualized.</div></td></tr></table> 18 0.0035 Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. <table style="text-align:start; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse; margin-top: 0;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; background-color: rgb(255, 206, 0); border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; color: rgb(0, 0, 0); vertical-align: bottom; width: auto; font-size: 10pt; line-height: normal; text-align: left; text-indent: 0px; letter-spacing: normal; text-transform: none; font-kerning: none; padding: 2pt 0px 1.5pt; margin-top: 0px; margin-bottom: 0px;"><div style="font-weight:bolder;display:inline;">Key Fund statistics</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Net Assets</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>2,034,134,744</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Number of Portfolio Holdings</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;">1</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt; text-indent: -6pt;">Portfolio Turnover Rate of the Master Portfolio</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt;">8<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div></td></tr></table> 2034134744 1 0.08 iShares Russell 1000 Large-Cap Index Fund Class K Shares BRGKX This semi-annual shareholder report contains important information about iShares Russell 1000 Large-Cap Index Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026. semi-annual shareholder report The Fund invests all of its assets in the Large Cap Index Master Portfolio (the “Master Portfolio”), a series of Master Investment Portfolio. You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441-7762. blackrock.com/fundreports (800) 441-7762 <div style="margin-top: 0; margin-right: 0; margin-bottom: -0.18pt; margin-left: 0; font-family: 'Arial'; font-kerning: none; font-weight: bold; font-size: 10pt; color: rgb(0, 0, 0);"><div style="font-weight:bolder;display:inline;">What were the </div> <div style="font-weight:bolder;display:inline;">Fund</div> <div style="font-weight:bolder;display:inline;"> costs for the </div> <div style="font-weight:bolder;display:inline;">last six mo<div style="display:inline;">n</div>ths</div> <div style="font-weight:bolder;display:inline;">?</div> </div><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-family: 'Arial'; font-size: 9pt; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none;">(based on a hypothetical $10,000 investment)</div> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); vertical-align: bottom; padding: 2pt 0px; text-align: left;"><div style="font-weight:bolder;display:inline;">Class name</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs of a $10,000<br/>investment</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs paid as a percentage of a<br/>$10,000 investment</div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; font-size: 8pt; line-height: 10pt; text-align: left;">Class K Shares</td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>3<div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; letter-spacing: 0px; top: 0px;display:inline;">(a)</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;">0.06<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(a)(b)</div></td></tr></table> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid; font-family: Arial; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding: 1.6pt 6pt 0px 0px; width: initial; vertical-align: top; text-indent: 0px; white-space: nowrap;"><div style="margin: 0px; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: Arial; font-style: normal; font-size: 7pt; line-height: 11pt; text-align: justify; vertical-align: top; padding: 0px; white-space: nowrap;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; white-space: nowrap;display:inline;">(a)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; text-indent: 0; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. </div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding-top: 0; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: initial; vertical-align: top; text-indent: 0;"><div style="margin-top: 0;margin-right: 0;margin-bottom: 0;margin-left: 0;font-weight: normal;color: rgb(0, 0, 0);font-kerning: none;font-family: 'Arial';font-style: normal;font-size: 7pt;line-height: 11pt;text-align: justify;vertical-align: top;padding-top: 0;padding-right: 0;padding-bottom: 0;padding-left: 0;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(b)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Annualized.</div></td></tr></table> 3 0.0006 Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. <table style="text-align:start; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse; margin-top: 0;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; background-color: rgb(255, 206, 0); border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; color: rgb(0, 0, 0); vertical-align: bottom; width: auto; font-size: 10pt; line-height: normal; text-align: left; text-indent: 0px; letter-spacing: normal; text-transform: none; font-kerning: none; padding: 2pt 0px 1.5pt; margin-top: 0px; margin-bottom: 0px;"><div style="font-weight:bolder;display:inline;">Key Fund statistics</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Net Assets</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>2,034,134,744</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Number of Portfolio Holdings</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;">1</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt; text-indent: -6pt;">Portfolio Turnover Rate of the Master Portfolio</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt;">8<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div></td></tr></table> 2034134744 1 0.08 iShares S&P 500 Index Fund Institutional Shares BSPIX This semi-annual shareholder report contains important information about iShares S&amp;P 500 Index Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026. semi-annual shareholder report The Fund invests all of its assets in the S&amp;P 500 Index Master Portfolio (the “Master Portfolio”), a series of Master Investment Portfolio. You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441-7762. blackrock.com/fundreports (800) 441-7762 <div style="font-family: 'Arial'; font-size: 9pt; font-weight: normal; color: rgb(0, 0, 0); margin-bottom: 5pt;"></div> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); vertical-align: bottom; padding: 2pt 0px; text-align: left;"><div style="font-weight:bolder;display:inline;">Class name</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs of a $10,000<br/>investment</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs paid as a percentage of a<br/>$10,000 investment</div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; font-size: 8pt; line-height: 10pt; text-align: left;">Institutional Shares</td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>5<div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; letter-spacing: 0px; top: 0px;display:inline;">(a)</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;">0.10<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(a)(b)</div></td></tr></table> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid; font-family: Arial; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding: 1.6pt 6pt 0px 0px; width: initial; vertical-align: top; text-indent: 0px; white-space: nowrap;"><div style="margin: 0px; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: Arial; font-style: normal; font-size: 7pt; line-height: 11pt; text-align: justify; vertical-align: top; padding: 0px; white-space: nowrap;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; white-space: nowrap;display:inline;">(a)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; text-indent: 0; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. </div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding-top: 0; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: initial; vertical-align: top; text-indent: 0;"><div style="margin-top: 0;margin-right: 0;margin-bottom: 0;margin-left: 0;font-weight: normal;color: rgb(0, 0, 0);font-kerning: none;font-family: 'Arial';font-style: normal;font-size: 7pt;line-height: 11pt;text-align: justify;vertical-align: top;padding-top: 0;padding-right: 0;padding-bottom: 0;padding-left: 0;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(b)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Annualized.</div></td></tr></table> 5 0.001 Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. <table style="text-align:start; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse; margin-top: 0;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; background-color: rgb(255, 206, 0); border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; color: rgb(0, 0, 0); vertical-align: bottom; width: auto; font-size: 10pt; line-height: normal; text-align: left; text-indent: 0px; letter-spacing: normal; text-transform: none; font-kerning: none; padding: 2pt 0px 1.5pt; margin-top: 0px; margin-bottom: 0px;"><div style="font-weight:bolder;display:inline;">Key Fund statistics</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Net Assets</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>59,061,952,467</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Number of Portfolio Holdings</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;">1</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt; text-indent: -6pt;">Portfolio Turnover Rate of the Master Portfolio</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt;">5<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div></td></tr></table> 59061952467 1 0.05 iShares S&P 500 Index Fund Service Shares BSPSX This semi-annual shareholder report contains important information about iShares S&amp;P 500 Index Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026. semi-annual shareholder report The Fund invests all of its assets in the S&amp;P 500 Index Master Portfolio (the “Master Portfolio”), a series of Master Investment Portfolio. You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441-7762. blackrock.com/fundreports (800) 441-7762 <div style="margin-top: 0; margin-right: 0; margin-bottom: -0.18pt; margin-left: 0; font-family: 'Arial'; font-kerning: none; font-weight: bold; font-size: 10pt; color: rgb(0, 0, 0);"><div style="font-weight:bolder;display:inline;">What were the </div> <div style="font-weight:bolder;display:inline;">Fund</div> <div style="font-weight:bolder;display:inline;"> costs for the </div> <div style="font-weight:bolder;display:inline;">last six months</div> <div style="font-weight:bolder;display:inline;">?</div> </div><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-family: 'Arial'; font-size: 9pt; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none;">(based on a hypothetical $10,000 investment)</div> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); vertical-align: bottom; padding: 2pt 0px; text-align: left;"><div style="font-weight:bolder;display:inline;">Class name</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs of a $10,000<br/>investment</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs paid as a percentage of a<br/>$10,000 investment</div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; font-size: 8pt; line-height: 10pt; text-align: left;">Service Shares</td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>11<div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; letter-spacing: 0px; top: 0px;display:inline;">(a)</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;">0.22<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(a)(b)</div></td></tr></table> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid; font-family: Arial; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding: 1.6pt 6pt 0px 0px; width: initial; vertical-align: top; text-indent: 0px; white-space: nowrap;"><div style="margin: 0px; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: Arial; font-style: normal; font-size: 7pt; line-height: 11pt; text-align: justify; vertical-align: top; padding: 0px; white-space: nowrap;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; white-space: nowrap;display:inline;">(a)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; text-indent: 0; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. </div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding-top: 0; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: initial; vertical-align: top; text-indent: 0;"><div style="margin-top: 0;margin-right: 0;margin-bottom: 0;margin-left: 0;font-weight: normal;color: rgb(0, 0, 0);font-kerning: none;font-family: 'Arial';font-style: normal;font-size: 7pt;line-height: 11pt;text-align: justify;vertical-align: top;padding-top: 0;padding-right: 0;padding-bottom: 0;padding-left: 0;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(b)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Annualized.</div></td></tr></table> 11 0.0022 Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. <table style="text-align:start; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse; margin-top: 0;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; background-color: rgb(255, 206, 0); border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; color: rgb(0, 0, 0); vertical-align: bottom; width: auto; font-size: 10pt; line-height: normal; text-align: left; text-indent: 0px; letter-spacing: normal; text-transform: none; font-kerning: none; padding: 2pt 0px 1.5pt; margin-top: 0px; margin-bottom: 0px;"><div style="font-weight:bolder;display:inline;">Key Fund statistics</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Net Assets</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>59,061,952,467</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Number of Portfolio Holdings</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;">1</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt; text-indent: -6pt;">Portfolio Turnover Rate of the Master Portfolio</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt;">5<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div></td></tr></table> 59061952467 1 0.05 iShares S&P 500 Index Fund Investor A Shares BSPAX This semi-annual shareholder report contains important information about iShares S&amp;P 500 Index Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026. semi-annual shareholder report The Fund invests all of its assets in the S&amp;P 500 Index Master Portfolio (the “Master Portfolio”), a series of Master Investment Portfolio. You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441-7762. blackrock.com/fundreports (800) 441-7762 <div style="margin-top: 0; margin-right: 0; margin-bottom: -0.18pt; margin-left: 0; font-family: 'Arial'; font-kerning: none; font-weight: bold; font-size: 10pt; color: rgb(0, 0, 0);"><div style="font-weight:bolder;display:inline;">What were the </div> <div style="font-weight:bolder;display:inline;">Fund</div> <div style="font-weight:bolder;display:inline;"> costs for the </div> <div style="font-weight:bolder;display:inline;">last six months</div> <div style="font-weight:bolder;display:inline;">?</div> </div><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-family: 'Arial'; font-size: 9pt; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none;">(based on a hypothetical $10,000 investment)</div> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); vertical-align: bottom; padding: 2pt 0px; text-align: left;"><div style="font-weight:bolder;display:inline;">Class name</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs of a $10,000<br/>investment</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs paid as a percentage of a<br/>$10,000 investment</div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; font-size: 8pt; line-height: 10pt; text-align: left;">Investor A Shares</td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>18<div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; letter-spacing: 0px; top: 0px;display:inline;">(a)</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;">0.35<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(a)(b)</div></td></tr></table> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid; font-family: Arial; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding: 1.6pt 6pt 0px 0px; width: initial; vertical-align: top; text-indent: 0px; white-space: nowrap;"><div style="margin: 0px; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: Arial; font-style: normal; font-size: 7pt; line-height: 11pt; text-align: justify; vertical-align: top; padding: 0px; white-space: nowrap;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; white-space: nowrap;display:inline;">(a)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; text-indent: 0; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. </div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding-top: 0; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: initial; vertical-align: top; text-indent: 0;"><div style="margin-top: 0;margin-right: 0;margin-bottom: 0;margin-left: 0;font-weight: normal;color: rgb(0, 0, 0);font-kerning: none;font-family: 'Arial';font-style: normal;font-size: 7pt;line-height: 11pt;text-align: justify;vertical-align: top;padding-top: 0;padding-right: 0;padding-bottom: 0;padding-left: 0;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(b)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Annualized.</div></td></tr></table> 18 0.0035 Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. <table style="text-align:start; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse; margin-top: 0;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; background-color: rgb(255, 206, 0); border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; color: rgb(0, 0, 0); vertical-align: bottom; width: auto; font-size: 10pt; line-height: normal; text-align: left; text-indent: 0px; letter-spacing: normal; text-transform: none; font-kerning: none; padding: 2pt 0px 1.5pt; margin-top: 0px; margin-bottom: 0px;"><div style="font-weight:bolder;display:inline;">Key Fund statistics</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Net Assets</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>59,061,952,467</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Number of Portfolio Holdings</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;">1</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt; text-indent: -6pt;">Portfolio Turnover Rate of the Master Portfolio</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt;">5<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div></td></tr></table> 59061952467 1 0.05 iShares S&P 500 Index Fund Investor P Shares BSPPX This semi-annual shareholder report contains important information about iShares S&amp;P 500 Index Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026. semi-annual shareholder report The Fund invests all of its assets in the S&amp;P 500 Index Master Portfolio (the “Master Portfolio”), a series of Master Investment Portfolio. You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441-7762. blackrock.com/fundreports (800) 441-7762 <div style="margin-top: 0; margin-right: 0; margin-bottom: -0.18pt; margin-left: 0; font-family: 'Arial'; font-kerning: none; font-weight: bold; font-size: 10pt; color: rgb(0, 0, 0);"><div style="font-weight:bolder;display:inline;">What were the </div> <div style="font-weight:bolder;display:inline;">Fund</div> <div style="font-weight:bolder;display:inline;"> costs for the </div> <div style="font-weight:bolder;display:inline;">last six months</div> <div style="font-weight:bolder;display:inline;">?</div> </div><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-family: 'Arial'; font-size: 9pt; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none;">(based on a hypothetical $10,000 investment)</div> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); vertical-align: bottom; padding: 2pt 0px; text-align: left;"><div style="font-weight:bolder;display:inline;">Class name</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs of a $10,000<br/>investment</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs paid as a percentage of a<br/>$10,000 investment</div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; font-size: 8pt; line-height: 10pt; text-align: left;">Investor P Shares</td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>18<div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; letter-spacing: 0px; top: 0px;display:inline;">(a)</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;">0.35<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(a)(b)</div></td></tr></table> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid; font-family: Arial; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding: 1.6pt 6pt 0px 0px; width: initial; vertical-align: top; text-indent: 0px; white-space: nowrap;"><div style="margin: 0px; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: Arial; font-style: normal; font-size: 7pt; line-height: 11pt; text-align: justify; vertical-align: top; padding: 0px; white-space: nowrap;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; white-space: nowrap;display:inline;">(a)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; text-indent: 0; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. </div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding-top: 0; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: initial; vertical-align: top; text-indent: 0;"><div style="margin-top: 0;margin-right: 0;margin-bottom: 0;margin-left: 0;font-weight: normal;color: rgb(0, 0, 0);font-kerning: none;font-family: 'Arial';font-style: normal;font-size: 7pt;line-height: 11pt;text-align: justify;vertical-align: top;padding-top: 0;padding-right: 0;padding-bottom: 0;padding-left: 0;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(b)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Annualized.</div></td></tr></table> 18 0.0035 Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. <table style="text-align:start; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse; margin-top: 0;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; background-color: rgb(255, 206, 0); border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; color: rgb(0, 0, 0); vertical-align: bottom; width: auto; font-size: 10pt; line-height: normal; text-align: left; text-indent: 0px; letter-spacing: normal; text-transform: none; font-kerning: none; padding: 2pt 0px 1.5pt; margin-top: 0px; margin-bottom: 0px;"><div style="font-weight:bolder;display:inline;">Key Fund statistics</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Net Assets</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>59,061,952,467</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Number of Portfolio Holdings</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;">1</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt; text-indent: -6pt;">Portfolio Turnover Rate of the Master Portfolio</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt;">5<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div></td></tr></table> 59061952467 1 0.05 iShares S&P 500 Index Fund Class G Shares BSPGX This semi-annual shareholder report contains important information about iShares S&amp;P 500 Index Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026. semi-annual shareholder report The Fund invests all of its assets in the S&amp;P 500 Index Master Portfolio (the “Master Portfolio”), a series of Master Investment Portfolio. You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441-7762. blackrock.com/fundreports (800) 441-7762 <div style="margin-top: 0; margin-right: 0; margin-bottom: -0.18pt; margin-left: 0; font-family: 'Arial'; font-kerning: none; font-weight: bold; font-size: 10pt; color: rgb(0, 0, 0);"><div style="font-weight:bolder;display:inline;">What were the </div> <div style="font-weight:bolder;display:inline;">Fund</div> <div style="font-weight:bolder;display:inline;"> costs for the </div> <div style="font-weight:bolder;display:inline;">last six months</div> <div style="font-weight:bolder;display:inline;">?</div> </div><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-family: 'Arial'; font-size: 9pt; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none;">(based on a hypothetical $10,000 investment)</div> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); vertical-align: bottom; padding: 2pt 0px; text-align: left;"><div style="font-weight:bolder;display:inline;">Class name</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs of a $10,000<br/>investment</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs paid as a percentage of a<br/>$10,000 investment</div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; font-size: 8pt; line-height: 10pt; text-align: left;">Class G Shares</td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>1<div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; letter-spacing: 0px; top: 0px;display:inline;">(a)</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;">0.01<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(a)(b)</div></td></tr></table> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid; font-family: Arial; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding: 1.6pt 6pt 0px 0px; width: initial; vertical-align: top; text-indent: 0px; white-space: nowrap;"><div style="margin: 0px; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: Arial; font-style: normal; font-size: 7pt; line-height: 11pt; text-align: justify; vertical-align: top; padding: 0px; white-space: nowrap;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; white-space: nowrap;display:inline;">(a)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; text-indent: 0; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. </div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding-top: 0; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: initial; vertical-align: top; text-indent: 0;"><div style="margin-top: 0;margin-right: 0;margin-bottom: 0;margin-left: 0;font-weight: normal;color: rgb(0, 0, 0);font-kerning: none;font-family: 'Arial';font-style: normal;font-size: 7pt;line-height: 11pt;text-align: justify;vertical-align: top;padding-top: 0;padding-right: 0;padding-bottom: 0;padding-left: 0;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(b)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Annualized.</div></td></tr></table> 1 0.0001 Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. <table style="text-align:start; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse; margin-top: 0;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; background-color: rgb(255, 206, 0); border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; color: rgb(0, 0, 0); vertical-align: bottom; width: auto; font-size: 10pt; line-height: normal; text-align: left; text-indent: 0px; letter-spacing: normal; text-transform: none; font-kerning: none; padding: 2pt 0px 1.5pt; margin-top: 0px; margin-bottom: 0px;"><div style="font-weight:bolder;display:inline;">Key Fund statistics</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Net Assets</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>59,061,952,467</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Number of Portfolio Holdings</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;">1</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt; text-indent: -6pt;">Portfolio Turnover Rate of the Master Portfolio</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt;">5<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div></td></tr></table> 59061952467 1 0.05 iShares S&P 500 Index Fund Class K Shares WFSPX This semi-annual shareholder report contains important information about iShares S&amp;P 500 Index Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026. semi-annual shareholder report The Fund invests all of its assets in the S&amp;P 500 Index Master Portfolio (the “Master Portfolio”), a series of Master Investment Portfolio. You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441-7762. blackrock.com/fundreports (800) 441-7762 <div style="margin-top: 0; margin-right: 0; margin-bottom: -0.18pt; margin-left: 0; font-family: 'Arial'; font-kerning: none; font-weight: bold; font-size: 10pt; color: rgb(0, 0, 0);"><div style="font-weight:bolder;display:inline;">What were the </div> <div style="font-weight:bolder;display:inline;">Fund</div> <div style="font-weight:bolder;display:inline;"> costs for the </div> <div style="font-weight:bolder;display:inline;">last six months</div> <div style="font-weight:bolder;display:inline;">?</div> </div><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-family: 'Arial'; font-size: 9pt; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none;">(based on a hypothetical $10,000 investment)</div> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); vertical-align: bottom; padding: 2pt 0px; text-align: left;"><div style="font-weight:bolder;display:inline;">Class name</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs of a $10,000<br/>investment</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs paid as a percentage of a<br/>$10,000 investment</div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; font-size: 8pt; line-height: 10pt; text-align: left;">Class K Shares</td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>2<div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; letter-spacing: 0px; top: 0px;display:inline;">(a)</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;">0.03<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(a)(b)</div></td></tr></table> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid; font-family: Arial; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding: 1.6pt 6pt 0px 0px; width: initial; vertical-align: top; text-indent: 0px; white-space: nowrap;"><div style="margin: 0px; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: Arial; font-style: normal; font-size: 7pt; line-height: 11pt; text-align: justify; vertical-align: top; padding: 0px; white-space: nowrap;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; white-space: nowrap;display:inline;">(a)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; text-indent: 0; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. </div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding-top: 0; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: initial; vertical-align: top; text-indent: 0;"><div style="margin-top: 0;margin-right: 0;margin-bottom: 0;margin-left: 0;font-weight: normal;color: rgb(0, 0, 0);font-kerning: none;font-family: 'Arial';font-style: normal;font-size: 7pt;line-height: 11pt;text-align: justify;vertical-align: top;padding-top: 0;padding-right: 0;padding-bottom: 0;padding-left: 0;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(b)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Annualized.</div></td></tr></table> 2 0.0003 Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. <table style="text-align:start; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse; margin-top: 0;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; background-color: rgb(255, 206, 0); border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; color: rgb(0, 0, 0); vertical-align: bottom; width: auto; font-size: 10pt; line-height: normal; text-align: left; text-indent: 0px; letter-spacing: normal; text-transform: none; font-kerning: none; padding: 2pt 0px 1.5pt; margin-top: 0px; margin-bottom: 0px;"><div style="font-weight:bolder;display:inline;">Key Fund statistics</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Net Assets</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>59,061,952,467</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Number of Portfolio Holdings</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;">1</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt; text-indent: -6pt;">Portfolio Turnover Rate of the Master Portfolio</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt;">5<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div></td></tr></table> 59061952467 1 0.05 iShares U.S. Aggregate Bond Index Fund Institutional Shares BMOIX This semi-annual shareholder report contains important information about iShares U.S. Aggregate Bond Index Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026. semi-annual shareholder report The Fund invests all of its assets in the U.S. Total Bond Index Master Portfolio (the “Master Portfolio”), a series of Master Investment Portfolio.  You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441-7762. blackrock.com/fundreports (800) 441-7762 <div style="margin-top: 0; margin-right: 0; margin-bottom: -0.18pt; margin-left: 0; font-family: 'Arial'; font-kerning: none; font-weight: bold; font-size: 10pt; color: rgb(0, 0, 0);"><div style="font-weight:bolder;display:inline;">What were the </div> <div style="font-weight:bolder;display:inline;">Fund</div> <div style="font-weight:bolder;display:inline;"> costs for the </div> <div style="font-weight:bolder;display:inline;">last six months</div> <div style="font-weight:bolder;display:inline;">?</div> </div><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-family: 'Arial'; font-size: 9pt; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none;">(based on a hypothetical $10,000 investment)</div> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); vertical-align: bottom; padding: 2pt 0px; text-align: left;"><div style="font-weight:bolder;display:inline;">Class name</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs of a $10,000<br/>investment</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs paid as a percentage of a<br/>$10,000 investment</div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; font-size: 8pt; line-height: 10pt; text-align: left;">Institutional Shares</td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>5<div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; letter-spacing: 0px; top: 0px;display:inline;">(a)</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;">0.10<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(a)(b)</div></td></tr></table> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid; font-family: Arial; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding: 1.6pt 6pt 0px 0px; width: initial; vertical-align: top; text-indent: 0px; white-space: nowrap;"><div style="margin: 0px; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: Arial; font-style: normal; font-size: 7pt; line-height: 11pt; text-align: justify; vertical-align: top; padding: 0px; white-space: nowrap;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; white-space: nowrap;display:inline;">(a)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; text-indent: 0; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. </div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding-top: 0; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: initial; vertical-align: top; text-indent: 0;"><div style="margin-top: 0;margin-right: 0;margin-bottom: 0;margin-left: 0;font-weight: normal;color: rgb(0, 0, 0);font-kerning: none;font-family: 'Arial';font-style: normal;font-size: 7pt;line-height: 11pt;text-align: justify;vertical-align: top;padding-top: 0;padding-right: 0;padding-bottom: 0;padding-left: 0;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(b)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Annualized.</div></td></tr></table> 5 0.001 Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. <table style="text-align:start; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse; margin-top: 0;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; background-color: rgb(255, 206, 0); border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; color: rgb(0, 0, 0); vertical-align: bottom; width: auto; font-size: 10pt; line-height: normal; text-align: left; text-indent: 0px; letter-spacing: normal; text-transform: none; font-kerning: none; padding: 2pt 0px 1.5pt; margin-top: 0px; margin-bottom: 0px;"><div style="font-weight:bolder;display:inline;">Key Fund statistics</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Net Assets</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>3,291,846,117</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Number of Portfolio Holdings</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;">1</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt; text-indent: -6pt;">Portfolio Turnover Rate of the Master Portfolio</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt;">46<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div></td></tr></table> 3291846117 1 0.46 iShares U.S. Aggregate Bond Index Fund Investor A Shares BMOAX This semi-annual shareholder report contains important information about iShares U.S. Aggregate Bond Index Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026. semi-annual shareholder report The Fund invests all of its assets in the U.S. Total Bond Index Master Portfolio (the “Master Portfolio”), a series of Master Investment Portfolio.  You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441-7762. blackrock.com/fundreports (800) 441-7762 <div style="margin-top: 0; margin-right: 0; margin-bottom: -0.18pt; margin-left: 0; font-family: 'Arial'; font-kerning: none; font-weight: bold; font-size: 10pt; color: rgb(0, 0, 0);"><div style="font-weight:bolder;display:inline;">What were the </div> <div style="font-weight:bolder;display:inline;">Fund</div> <div style="font-weight:bolder;display:inline;"> costs for the </div> <div style="font-weight:bolder;display:inline;">last six months</div> <div style="font-weight:bolder;display:inline;">?</div> </div><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-family: 'Arial'; font-size: 9pt; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none;">(based on a hypothetical $10,000 investment)</div> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); vertical-align: bottom; padding: 2pt 0px; text-align: left;"><div style="font-weight:bolder;display:inline;">Class name</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs of a $10,000<br/>investment</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs paid as a percentage of a<br/>$10,000 investment</div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; font-size: 8pt; line-height: 10pt; text-align: left;">Investor A Shares</td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>17<div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; letter-spacing: 0px; top: 0px;display:inline;">(a)</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;">0.35<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(a)(b)</div></td></tr></table> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid; font-family: Arial; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding: 1.6pt 6pt 0px 0px; width: initial; vertical-align: top; text-indent: 0px; white-space: nowrap;"><div style="margin: 0px; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: Arial; font-style: normal; font-size: 7pt; line-height: 11pt; text-align: justify; vertical-align: top; padding: 0px; white-space: nowrap;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; white-space: nowrap;display:inline;">(a)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; text-indent: 0; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. </div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding-top: 0; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: initial; vertical-align: top; text-indent: 0;"><div style="margin-top: 0;margin-right: 0;margin-bottom: 0;margin-left: 0;font-weight: normal;color: rgb(0, 0, 0);font-kerning: none;font-family: 'Arial';font-style: normal;font-size: 7pt;line-height: 11pt;text-align: justify;vertical-align: top;padding-top: 0;padding-right: 0;padding-bottom: 0;padding-left: 0;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(b)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Annualized.</div></td></tr></table> 17 0.0035 Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. <table style="text-align:start; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse; margin-top: 0;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; background-color: rgb(255, 206, 0); border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; color: rgb(0, 0, 0); vertical-align: bottom; width: auto; font-size: 10pt; line-height: normal; text-align: left; text-indent: 0px; letter-spacing: normal; text-transform: none; font-kerning: none; padding: 2pt 0px 1.5pt; margin-top: 0px; margin-bottom: 0px;"><div style="font-weight:bolder;display:inline;">Key Fund statistics</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Net Assets</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>3,291,846,117</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Number of Portfolio Holdings</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;">1</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt; text-indent: -6pt;">Portfolio Turnover Rate of the Master Portfolio</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt;">46<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div></td></tr></table> 3291846117 1 0.46 iShares U.S. Aggregate Bond Index Fund Investor P Shares BMOPX This semi-annual shareholder report contains important information about iShares U.S. Aggregate Bond Index Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026. semi-annual shareholder report The Fund invests all of its assets in the U.S. Total Bond Index Master Portfolio (the “Master Portfolio”), a series of Master Investment Portfolio.  You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441-7762. blackrock.com/fundreports (800) 441-7762 <div style="margin-top: 0; margin-right: 0; margin-bottom: -0.18pt; margin-left: 0; font-family: 'Arial'; font-kerning: none; font-weight: bold; font-size: 10pt; color: rgb(0, 0, 0);"><div style="font-weight:bolder;display:inline;">What were the </div> <div style="font-weight:bolder;display:inline;">Fund</div> <div style="font-weight:bolder;display:inline;"> costs for the </div> <div style="font-weight:bolder;display:inline;">last six months</div> <div style="font-weight:bolder;display:inline;">?</div> </div><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-family: 'Arial'; font-size: 9pt; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none;">(based on a hypothetical $10,000 investment)</div> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); vertical-align: bottom; padding: 2pt 0px; text-align: left;"><div style="font-weight:bolder;display:inline;">Class name</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs of a $10,000<br/>investment</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs paid as a percentage of a<br/>$10,000 investment</div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; font-size: 8pt; line-height: 10pt; text-align: left;">Investor P Shares</td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>17<div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; letter-spacing: 0px; top: 0px;display:inline;">(a)</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;">0.35<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(a)(b)</div></td></tr></table> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid; font-family: Arial; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding: 1.6pt 6pt 0px 0px; width: initial; vertical-align: top; text-indent: 0px; white-space: nowrap;"><div style="margin: 0px; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: Arial; font-style: normal; font-size: 7pt; line-height: 11pt; text-align: justify; vertical-align: top; padding: 0px; white-space: nowrap;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; white-space: nowrap;display:inline;">(a)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; text-indent: 0; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. </div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding-top: 0; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: initial; vertical-align: top; text-indent: 0;"><div style="margin-top: 0;margin-right: 0;margin-bottom: 0;margin-left: 0;font-weight: normal;color: rgb(0, 0, 0);font-kerning: none;font-family: 'Arial';font-style: normal;font-size: 7pt;line-height: 11pt;text-align: justify;vertical-align: top;padding-top: 0;padding-right: 0;padding-bottom: 0;padding-left: 0;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(b)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Annualized.</div></td></tr></table> 17 0.0035 Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. <table style="text-align:start; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse; margin-top: 0;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; background-color: rgb(255, 206, 0); border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; color: rgb(0, 0, 0); vertical-align: bottom; width: auto; font-size: 10pt; line-height: normal; text-align: left; text-indent: 0px; letter-spacing: normal; text-transform: none; font-kerning: none; padding: 2pt 0px 1.5pt; margin-top: 0px; margin-bottom: 0px;"><div style="font-weight:bolder;display:inline;">Key Fund statistics</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Net Assets</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>3,291,846,117</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Number of Portfolio Holdings</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;">1</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt; text-indent: -6pt;">Portfolio Turnover Rate of the Master Portfolio</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt;">46<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div></td></tr></table> 3291846117 1 0.46 iShares U.S. Aggregate Bond Index Fund Class K Shares WFBIX This semi-annual shareholder report contains important information about iShares U.S. Aggregate Bond Index Fund (the “Fund”) for the period of January 1, 2026 to June 30, 2026. semi-annual shareholder report The Fund invests all of its assets in the U.S. Total Bond Index Master Portfolio (the “Master Portfolio”), a series of Master Investment Portfolio.  You can find additional information about the Fund at blackrock.com/fundreports. You can also request this information by contacting us at (800) 441-7762. blackrock.com/fundreports (800) 441-7762 <div style="margin-top: 0; margin-right: 0; margin-bottom: -0.18pt; margin-left: 0; font-family: 'Arial'; font-kerning: none; font-weight: bold; font-size: 10pt; color: rgb(0, 0, 0);"><div style="font-weight:bolder;display:inline;">What were the </div> <div style="font-weight:bolder;display:inline;">Fund</div> <div style="font-weight:bolder;display:inline;"> costs for the </div> <div style="font-weight:bolder;display:inline;">last six months</div> <div style="font-weight:bolder;display:inline;">?</div> </div><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-family: 'Arial'; font-size: 9pt; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none;">(based on a hypothetical $10,000 investment)</div> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); vertical-align: bottom; padding: 2pt 0px; text-align: left;"><div style="font-weight:bolder;display:inline;">Class name</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs of a $10,000<br/>investment</div></td> <td style="break-inside: avoid; font-family: Arial; font-size: 9pt; color: rgb(0, 0, 0); font-kerning: none; line-height: 11pt; background-color: rgb(255, 206, 0); text-align: center; vertical-align: bottom; padding: 2pt 0px;"><div style="font-weight:bolder;display:inline;">Costs paid as a percentage of a<br/>$10,000 investment</div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; font-size: 8pt; line-height: 10pt; text-align: left;">Class K Shares</td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>2<div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; letter-spacing: 0px; top: 0px;display:inline;">(a)</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; vertical-align: bottom; padding-top: 4pt; padding-right: 0; padding-bottom: 2pt; padding-left: 0; text-align: center; font-size: 8pt; line-height: 10pt; white-space: nowrap;">0.05<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(a)(b)</div></td></tr></table> <table style="text-align:start; margin-top: 2pt; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse;"> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid; font-family: Arial; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding: 1.6pt 6pt 0px 0px; width: initial; vertical-align: top; text-indent: 0px; white-space: nowrap;"><div style="margin: 0px; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: Arial; font-style: normal; font-size: 7pt; line-height: 11pt; text-align: justify; vertical-align: top; padding: 0px; white-space: nowrap;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0; white-space: nowrap;display:inline;">(a)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; text-indent: 0; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. </div></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; padding-top: 0; padding-right: 6pt; padding-bottom: 0; padding-left: 0; width: initial; vertical-align: top; text-indent: 0;"><div style="margin-top: 0;margin-right: 0;margin-bottom: 0;margin-left: 0;font-weight: normal;color: rgb(0, 0, 0);font-kerning: none;font-family: 'Arial';font-style: normal;font-size: 7pt;line-height: 11pt;text-align: justify;vertical-align: top;padding-top: 0;padding-right: 0;padding-bottom: 0;padding-left: 0;"><div style="vertical-align: 0.5em; font-size: smaller; line-height: 0;display:inline;">(b)</div></div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0; width: 100%;"><div style="margin-top: 0; margin-right: 0; margin-bottom: 0; margin-left: 0; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-family: 'Arial'; font-style: normal; font-size: 7pt; line-height: 9pt; text-align: justify; vertical-align: top; padding-top: 0; padding-right: 0; padding-bottom: 0; padding-left: 0;">Annualized.</div></td></tr></table> 2 0.0005 Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio. <table style="text-align:start; break-inside: avoid-page; page-break-inside: avoid; table-layout: auto; width: 100%; border-collapse: collapse; margin-top: 0;"> <tr style="break-after: avoid; break-inside: avoid-page; page-break-inside: avoid; height: auto; background-color: rgb(255, 206, 0); border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid; font-family: Arial; color: rgb(0, 0, 0); vertical-align: bottom; width: auto; font-size: 10pt; line-height: normal; text-align: left; text-indent: 0px; letter-spacing: normal; text-transform: none; font-kerning: none; padding: 2pt 0px 1.5pt; margin-top: 0px; margin-bottom: 0px;"><div style="font-weight:bolder;display:inline;">Key Fund statistics</div></td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"></td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Net Assets</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;"><div style="float: none; letter-spacing: 0px; top: 0px;display:inline;">$</div>3,291,846,117</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: initial; border-bottom-style: none; border-bottom-width: initial;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt; text-indent: -6pt;">Number of Portfolio Holdings</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 0; padding-left: 6pt;">1</td></tr> <tr style="break-inside: avoid-page; page-break-inside: avoid; height: auto; border-bottom-color: rgb(0, 0, 0); border-bottom-style: solid; border-bottom-width: 0.5pt;"> <td style="break-inside: avoid-page; page-break-inside: avoid; font-family: 'Arial'; color: rgb(0, 0, 0); font-kerning: none; overflow-x: hidden; font-size: 8pt; line-height: 10pt; font-weight: normal; text-align: left; width: 100%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt; text-indent: -6pt;">Portfolio Turnover Rate of the Master Portfolio</td> <td style="break-inside: avoid-page; page-break-inside: avoid; text-align: right; font-family: 'Arial'; font-weight: normal; color: rgb(0, 0, 0); font-kerning: none; white-space: nowrap; font-size: 8pt; line-height: 10pt; width: 12%; vertical-align: bottom; padding-top: 1.6pt; padding-right: 6pt; padding-bottom: 1.6pt; padding-left: 6pt;">46<div style="letter-spacing: 0px; top: 0px;display:inline;">%</div></td></tr></table> 3291846117 1 0.46 Because the Fund invests all of its assets in the Master Portfolio, the expense example reflects the net expenses of both the Fund and the Master Portfolio.  Annualized.