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N-1A
BLACKROCK FINANCIAL INSTITUTIONS SERIES TRUST
2026-08-28
Fund Overview Key Facts About BlackRock Summit Cash Reserves Fund
Investment Objective
<div style="margin-top: 6pt;"><span style="color: #000000; font-family: arial; font-size: 9.30pt;">The investment objective of BlackRock Summit Cash Reserves Fund (the “Fund”) of BlackRock Financial Institutions </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">Series Trust (the “Trust”) is to seek current income, preservation of capital and liquidity available from investing in a </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">diversified portfolio of short-term money market securities.</span></div>
Fees and Expenses of the Fund
<div style="margin-top: 6pt;"><span style="color: #000000; font-family: arial; font-size: 9.30pt;">This table describes the fees and expenses that you may pay if you buy, hold and sell shares of the Fund. Amounts in </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">the table are rounded to the nearest basis point, which in some cases may be “0.00”.</span><span style="color: #000000; font-family: arial; font-size: 9.30pt; font-weight: bold;">You may pay other fees, such </span><span style="color: #000000; font-family: arial; font-size: 9.30pt; font-weight: bold;">as brokerage commissions and other fees to your financial professional or your selected securities dealer, broker, </span><span style="color: #000000; font-family: arial; font-size: 9.30pt; font-weight: bold;">investment adviser, service provider or industry professional (including BlackRock Advisors, LLC (“BlackRock”) and </span><span style="color: #000000; font-family: arial; font-size: 9.30pt; font-weight: bold;">its affiliates) (each a “Financial Intermediary”), which are not reflected in the table and example below.</span><span style="color: #000000; font-family: arial; font-size: 9.30pt;"> More </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">information about these fees and expenses is available from your Financial Intermediary and in the “Details About the </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">Share Classes” and the “Intermediary-Defined Sales Charge Waiver Policies” sections on pages </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">19</span><span style="color: #000000; font-family: arial; font-size: 9.30pt;"> and </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">A-1</span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">, </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">respectively, of the Fund’s prospectus and in the “Purchase of Shares” section on page </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">II-41</span><span style="color: #000000; font-family: arial; font-size: 9.30pt;"> of Part II of the Fund’s </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">Statement of Additional Information.</span><span style="color: #000000; font-family: arial; font-size: 1pt; line-height: 0.93pt;"> </span></div>
Shareholder Fees (fees paid directly from your investment)
0
0
0
0
0.0100
0
Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
0.0050
0.0050
0.0050
0
0.0075
0
0.0005
0.0031
0.0007
0.0055
0.0156
0.0057
-0.0013
-0.0039
-0.0015
0.0042
0.0117
0.0042
There is no contingent deferred sales charge (“CDSC”) on Investor A Shares purchased directly. However, a CDSC of up to 1.00% may apply to certain redemptions of the Fund’s Investor A Shares purchased in an exchange transaction for Investor A Shares of a fund advised by BlackRock or its affiliates where no initial sales charge was paid at the time of purchase of such fund (each, an “Investor A Load-Waived BlackRock Fund”) as part of an investment of $1,000,000 (lesser amounts may apply depending on the Investor A Load-Waived BlackRock Fund) or more. The Investor A Shares CDSC is only charged upon redemptions of Investor A Shares within 18 months after you originally acquired such Investor A Shares of the Investor A Load-Waived BlackRock Fund (a shorter holding period may apply depending on the Investor A Load-Waived BlackRock Fund), unless you qualify for a waiver. There is no CDSC charged on redemptions if you have owned your Investor A Shares for more than 18 months (or for a shorter holding period, as applicable) as measured from your original purchase of Investor A Shares that you exchanged into Investor A Shares of the Fund or if you purchase Investor A Shares of the Fund not through an exchange.
June 30, 2028
Example:
<div style="line-height: 10.695pt; text-align: left;"><span style="color: #000000; font-family: arial; font-size: 9.30pt;">This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">mutual funds. The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">return each year and that the Fund’s operating expenses remain the same. Although your actual costs may be higher </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">or lower, based on these assumptions your costs would be:</span><span style="color: #000000; font-family: arial; font-size: 1pt; line-height: 0.93pt;"> </span></div>
43
163
294
677
219
454
813
1550
43
168
303
699
You would pay the following expenses if you did not redeem your shares:
119
454
813
1550
Principal Investment Strategies of the Fund
<div style="margin-top: 6pt;"><span style="color: #000000; font-family: arial; font-size: 9.30pt;">The Fund invests at least 99.5% of its total assets in cash, U.S. Treasury bills, notes and other obligations issued or guaranteed as to principal and interest by the U.S. Government, its agencies or instrumentalities, and repurchase agreements secured by such obligations or cash. The Fund invests in securities maturing in 397 days (13 months) or less (with certain exceptions), and the portfolio will have a dollar-weighted average maturity of 60 days or less and a dollar-weighted average life of 120 days or less. The Fund may invest in variable and floating rate instruments, and transact in securities on a when-issued, delayed delivery or forward commitment basis.</span><span style="color: #000000; font-family: arial; font-size: 9.30pt; line-height: 10.695pt;"> </span></div> <div style="margin-top: 6pt;"><span style="color: #000000; font-family: arial; font-size: 9.30pt;">The securities purchased by the Fund are subject to the quality, diversification, and other requirements of Rule 2a-7 under the Investment Company Act of 1940, as amended (the “Investment Company Act”), and other rules of the Securities and Exchange Commission.</span><span style="color: #000000; font-family: arial; font-size: 9.30pt; line-height: 10.695pt;"> </span></div>
You could lose money by investing in the Fund.
Although the Fund seeks to preserve the value of your investment at $1.00 per share, it cannot guarantee it will do so.
An investment in the Fund is not a bank account and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other government agency.
The Fund’s sponsor is not required to reimburse the Fund for losses, and you should not expect that the sponsor will provide financial support to the Fund at any time, including during periods of market stress.
<div> <div style="clear: both; margin-top: 4.805pt; position: relative; width: 100%;"> <div style="float: left; line-height: 9.87pt; text-align: left; width: 8pt;"><span style="color: #000000; font-family: arial; font-size: 8.37pt; position: relative; top: -0.5pt;">◼</span></div> <div style="float: left; line-height: 10.80pt; margin-left: 4pt; text-align: left; width: 505.0pt;"><span style="color: #000000; font-family: arial; font-size: 9.30pt; font-style: italic; font-weight: bold;">Interest Rate Risk </span><span style="color: #000000; font-family: arial; font-size: 9.30pt; font-style: italic;">—</span><span style="color: #000000; font-family: arial; font-size: 9.30pt;"> Interest rate risk is the risk that the value of a debt security may fall when interest rates rise. </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">In general, the market price of debt securities with longer maturities will go up or down more in response to changes </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">in interest rates than the market price of shorter-term securities. Due to fluctuations in interest rates, the market </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">value of such securities may vary during the period shareholders own shares of the Fund. Very low or negative </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">interest rates may magnify interest rate risk. During periods of very low or negative interest rates, the Fund may be </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">unable to maintain positive returns or pay dividends to Fund shareholders. The Fund may be subject to a greater </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">risk of rising interest rates during a period of low interest rates. Changing interest rates may have unpredictable </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">effects on markets, may result in heightened market volatility and may detract from the Fund’s ability to achieve its </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">investment objective.</span></div> </div> <div style="clear: both; position: relative;"> </div> </div>
<div> <div style="clear: both; margin-top: 4.805pt; position: relative; width: 100%;"> <div style="float: left; line-height: 9.87pt; text-align: left; width: 8pt;"><span style="color: #000000; font-family: arial; font-size: 8.37pt; position: relative; top: -0.5pt;">◼</span></div> <div style="float: left; line-height: 10.80pt; margin-left: 4pt; text-align: left; width: 505.00pt;"><span style="color: #000000; font-family: arial; font-size: 9.30pt; font-style: italic; font-weight: bold;">Treasury Obligations Risk </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">— Direct obligations of the U.S. Treasury have historically involved little risk of loss of </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">principal if held to maturity. However, due to fluctuations in interest rates, the market value of such securities may </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">vary during the period shareholders own shares of the Fund. In addition, notwithstanding that U.S. Treasury </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">obligations are backed by the full faith and credit of the United States, circumstances could arise that could prevent </span></div> </div> <div style="clear: both; position: relative;"> </div> </div> <div style="line-height: 10.695pt; margin-left: 12pt; text-align: left;"><span style="color: #000000; font-family: arial; font-size: 9.30pt;">the timely payment of interest or principal, such as reaching the legislative “debt ceiling.” Such non-payment could </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">result in losses to the Fund and substantial negative consequences for the U.S. economy and the global financial </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">system.</span></div>
<div> <div style="clear: both; margin-top: 4.805pt; position: relative; width: 100%;"> <div style="float: left; line-height: 9.87pt; text-align: left; width: 8pt;"><span style="color: #000000; font-family: arial; font-size: 8.37pt; position: relative; top: -0.5pt;">◼</span></div> <div style="float: left; line-height: 10.80pt; margin-left: 4pt; text-align: left; width: 505.00pt;"><span style="color: #000000; font-family: arial; font-size: 9.30pt; font-style: italic; font-weight: bold;">U.S. Government Obligations Risk </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">— Certain securities in which the Fund may invest, including securities issued by </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">certain U.S. Government agencies and U.S. Government sponsored enterprises, are not guaranteed by the U.S. </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">Government or supported by the full faith and credit of the United States. In addition, circumstances could arise </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">that could prevent the timely payment of interest or principal on U.S. Government obligations, such as reaching the </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">legislative “debt ceiling.” Such non-payment could result in losses to the Fund and substantial negative </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">consequences for the U.S. economy and the global financial system.</span></div> </div> <div style="clear: both; position: relative;"> </div> </div>
<div> <div style="clear: both; margin-top: 4.805pt; position: relative; width: 100%;"> <div style="float: left; line-height: 9.87pt; text-align: left; width: 8pt;"><span style="color: #000000; font-family: arial; font-size: 8.37pt; position: relative; top: -0.5pt;">◼</span></div> <div style="float: left; line-height: 10.80pt; margin-left: 4pt; text-align: left; width: 505.00pt;"><span style="color: #000000; font-family: arial; font-size: 9.30pt; font-style: italic; font-weight: bold;">Repurchase Agreements Risk</span><span style="color: #000000; font-family: arial; font-size: 9.30pt;"> — If the other party to a repurchase agreement defaults on its obligation under the </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">agreement, the Fund may suffer delays and incur costs or lose money in exercising its rights under the agreement. </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">If the seller fails to repurchase the security and the market value of the security declines, the Fund may lose money.</span></div> </div> <div style="clear: both; position: relative;"> </div> </div>
<div> <div style="clear: both; margin-top: 4.805pt; position: relative; width: 100%;"> <div style="float: left; line-height: 9.87pt; text-align: left; width: 8pt;"><span style="color: #000000; font-family: arial; font-size: 8.37pt; position: relative; top: -0.5pt;">◼</span></div> <div style="float: left; line-height: 10.80pt; margin-left: 4pt; text-align: left; width: 505.00pt;"><span style="color: #000000; font-family: arial; font-size: 9.30pt; font-style: italic; font-weight: bold;">Credit Risk</span><span style="color: #000000; font-family: arial; font-size: 9.30pt;"> — Credit risk refers to the possibility that the issuer of a debt security (i.e., the borrower) will be unable </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">or unwilling to make timely payments of interest and principal when due or otherwise honor their obligations. </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">Changes in an issuer’s credit rating or the market’s perception of an issuer’s creditworthiness may also affect the </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">value of the Fund’s investment in that issuer.</span><span style="color: #000000; font-family: arial; font-size: 9.30pt; line-height: 10.695pt;"> </span></div> </div> <div style="clear: both; position: relative;"> </div> </div>
<div> <div style="clear: both; margin-top: 4.805pt; position: relative; width: 100%;"> <div style="float: left; line-height: 9.87pt; text-align: left; width: 8pt;"><span style="color: #000000; font-family: arial; font-size: 8.37pt; position: relative; top: -0.5pt;">◼</span></div> <div style="float: left; line-height: 10.80pt; margin-left: 4pt; text-align: left; width: 505.00pt;"><span style="color: #000000; font-family: arial; font-size: 9.30pt; font-style: italic; font-weight: bold;">Income Risk</span><span style="color: #000000; font-family: arial; font-size: 9.30pt;"> — Income risk is the risk that the Fund’s yield will vary as short-term securities in its portfolio mature </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">and the proceeds are reinvested in securities with different interest rates.</span><span style="color: #000000; font-family: arial; font-size: 9.30pt; line-height: 10.695pt;"> </span></div> </div> <div style="clear: both; position: relative;"> </div> </div>
<div> <div style="clear: both; margin-top: 4.805pt; position: relative; width: 100%;"> <div style="float: left; line-height: 9.87pt; text-align: left; width: 8pt;"><span style="color: #000000; font-family: arial; font-size: 8.37pt; position: relative; top: -0.5pt;">◼</span></div> <div style="float: left; line-height: 10.80pt; margin-left: 4pt; text-align: left; width: 505.00pt;"><span style="color: #000000; font-family: arial; font-size: 9.30pt; font-style: italic; font-weight: bold;">Market Risk and Selection Risk </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">— Market risk is the risk that one or more markets in which the Fund invests will </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">go down in value, including the possibility that the markets will go down sharply and unpredictably. Securities or </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">other investments held by the Fund may underperform the markets, the relevant indices or benchmarks, or the </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">securities selected by other funds with similar investment objectives and investment strategies, or may otherwise </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">fail to perform as intended. The value of a security or other asset may decline due to changes in general market </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">conditions, economic trends or events that are not specifically related to the issuer of the security or other asset, or </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">factors that affect a particular issuer or issuers, exchange, country, group of countries, region, market, industry, </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">group of industries, sector or asset class. The success of the Fund’s activities could be affected by interest rates, </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">availability of credit, inflation rates, economic uncertainty, changes in laws, tariffs and trade barriers, supply chain </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">disruptions, economic sanctions, currency exchange controls, and local, regional or global events such as war, acts </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">of terrorism, natural and environmental disasters, the spread of infectious illness or other public health issues, </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">recessions, or other events.</span><span style="color: #000000; font-family: arial; font-size: 9.30pt; line-height: 10.695pt;"> </span></div> </div> <div style="clear: both; position: relative;"> </div> </div> <div style="margin-top: 4pt;"><span style="color: #000000; font-family: arial; font-size: 9.30pt;">Recent policy initiatives undertaken by the U.S. government have the potential to impact international relations, </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">trade agreements and the overall regulatory environment in ways that could create uncertainty and instability in </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">domestic and global markets, and could adversely affect the investment performance of the Fund. In particular, </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">actions taken by the U.S. government in respect of international trade relations could lead to trade wars, increased </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">costs for imported goods, disruptions in supply chains, reduced foreign investment, and instability in regions where </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">the Fund invests.</span></div>
<div> <div style="clear: both; margin-top: 4.805pt; position: relative; width: 100%;"> <div style="float: left; line-height: 9.87pt; text-align: left; width: 8pt;"><span style="color: #000000; font-family: arial; font-size: 8.37pt; position: relative; top: -0.5pt;">◼</span></div> <div style="float: left; line-height: 10.80pt; margin-left: 4pt; text-align: left; width: 505.00pt;"><span style="color: #000000; font-family: arial; font-size: 9.30pt; font-style: italic; font-weight: bold;">Operational and Technology Risks </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">— The Fund is directly and indirectly susceptible to operational and technology </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">risks, including those related to human errors, processing errors, communication errors, systems failures, </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">cybersecurity incidents, and the use of artificial intelligence and machine learning (“AI”), which may result in losses </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">for the Fund and its shareholders or may impair the Fund’s operations. While the Fund’s service providers are </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">required to have appropriate operational, information security and cybersecurity risk management policies and </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">procedures, their methods of risk management may differ from those of the Fund. Operational and technology risks </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">for the issuers in which the Fund invests could also result in material adverse consequences for such issuers and </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">may cause the Fund’s investments in such issuers to lose value.</span></div> </div> <div style="clear: both; position: relative;"> </div> </div>
<div> <div style="clear: both; margin-top: 4.805pt; position: relative; width: 100%;"> <div style="float: left; line-height: 9.87pt; text-align: left; width: 8pt;"><span style="color: #000000; font-family: arial; font-size: 8.37pt; position: relative; top: -0.5pt;">◼</span></div> <div style="float: left; line-height: 10.80pt; margin-left: 4pt; text-align: left; width: 505.00pt;"><span style="color: #000000; font-family: arial; font-size: 9.30pt; font-style: italic; font-weight: bold;">Risk of Investing in the United States</span><span style="color: #000000; font-family: arial; font-size: 9.30pt;"> — Certain changes in the U.S. economy, such as when the U.S. economy </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">weakens or when its financial markets decline, may have an adverse effect on the securities to which the Fund has </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">exposure.</span></div> </div> <div style="clear: both; position: relative;"> </div> </div>
<div> <div style="clear: both; margin-top: 4.805pt; position: relative; width: 100%;"> <div style="float: left; line-height: 9.87pt; text-align: left; width: 8pt;"><span style="color: #000000; font-family: arial; font-size: 8.37pt; position: relative; top: -0.5pt;">◼</span></div> <div style="float: left; line-height: 10.80pt; margin-left: 4pt; text-align: left; width: 505.00pt;"><span style="color: #000000; font-family: arial; font-size: 9.30pt; font-style: italic; font-weight: bold;">Stable Net Asset Value Risk </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">— The Fund may not be able to maintain a stable NAV of $1.00 per share at all times. </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">If the Fund fails to maintain a stable NAV (or if there is a perceived threat of such a failure), the Fund, along with </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">other money market funds, could be subject to increased redemption activity.</span></div> </div> <div style="clear: both; position: relative;"> </div> </div>
<div> <div style="clear: both; margin-top: 4.805pt; position: relative; width: 100%;"> <div style="float: left; line-height: 9.87pt; text-align: left; width: 8pt;"><span style="color: #000000; font-family: arial; font-size: 8.37pt; position: relative; top: -0.5pt;">◼</span></div> <div style="float: left; line-height: 10.80pt; margin-left: 4pt; text-align: left; width: 505.00pt;"><span style="color: #000000; font-family: arial; font-size: 9.30pt; font-style: italic; font-weight: bold;">Variable and Floating Rate Instrument Risk </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">— Variable and floating rate securities provide for periodic adjustment </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">in the interest rate paid on the securities. Securities with floating or variable interest rates can be less sensitive to </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">interest rate changes than securities with fixed interest rates, but may decline in value if their coupon rates do not </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">reset as high, or as quickly, as comparable market interest rates, and generally carry lower yields than fixed </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">securities of the same maturity. These securities will not generally increase in value if interest rates decline. A </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">decline in interest rates may result in a reduction in income received from variable and floating rate securities held </span></div> </div> <div style="clear: both; position: relative;"> </div> </div> <div style="line-height: 10.695pt; margin-left: 12pt; text-align: left;"><span style="color: #000000; font-family: arial; font-size: 9.30pt;">by the Fund and may adversely affect the value of the Fund’s shares. Benchmark interest rates may not accurately </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">track market interest rates. Although floating rate securities are less sensitive to interest rate risk than fixed-rate </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">securities, they are subject to credit risk and default risk, which could impair their value.</span></div>
<div> <div style="clear: both; margin-top: 4.805pt; position: relative; width: 100%;"> <div style="float: left; line-height: 9.87pt; text-align: left; width: 8pt;"><span style="color: #000000; font-family: arial; font-size: 8.37pt; position: relative; top: -0.5pt;">◼</span></div> <div style="float: left; line-height: 10.80pt; margin-left: 4pt; text-align: left; width: 505.00pt;"><span style="color: #000000; font-family: arial; font-size: 9.30pt; font-style: italic; font-weight: bold;">When-Issued and Delayed Delivery Securities and Forward Commitments Risk </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">— When-issued and delayed </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">delivery securities and forward commitments involve the risk that the security the Fund buys will lose value prior to </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">its delivery. There also is the risk that the security will not be issued or that the other party to the transaction will </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">not meet its obligation. If this occurs, the Fund may lose both the investment opportunity for the assets it set aside </span><span style="color: #000000; font-family: arial; font-size: 9.30pt;">to pay for the security and any gain in the security’s price.</span></div> </div> <div style="clear: both; position: relative;"> </div> </div>
Performance Information
<div style="margin-top: 6pt;"><span style="color: #000000; font-family: arial; font-size: 9.30pt;">The Fund is a money market fund managed pursuant to the requirements of Rule 2a-7 under the Investment Company Act. Institutional Shares commenced operations on July 15, 2019. As a result, the returns shown below for Institutional Shares prior to July 15, 2019 are those of the Fund’s Investor A Shares. The performance of Institutional Shares would be substantially similar to Investor A Shares because Institutional Shares and Investor A Shares are invested in the same portfolio of securities and performance would differ only to the extent that Institutional Shares and Investor A Shares have different expenses. The actual returns of Institutional Shares would have been approximately the same as those of the Investor A Shares because Institutional Shares have the same expenses as the Investor A Shares. Investor C Shares commenced operations on August 10, 2018. As a result, the returns shown below for Investor C Shares prior to August 10, 2018 are those of the Fund’s Investor A Shares, adjusted to reflect the fees and expenses applicable to Investor C Shares. Effective January 4, 2016, the Fund changed its investment strategies in order to be categorized as a “government money market fund” under Rule 2a-7, as more fully described in “Fund Overview — Principal Investment Strategies of the Fund.” Performance for the periods shown below prior to January 4, 2016 is based on the prior investment strategy utilized by the Fund, which permitted investment in a wider range of money market securities and instruments and was not constrained by the requirement to invest at least 99.5% of the Fund’s assets in cash, U.S. Government securities and repurchase agreements secured by such securities or cash. The information below shows you how the Fund’s performance has varied year by year and provides some indication of the risks of investing in the Fund. As with all such investments, past performance is not an indication of future results. To the extent that dividends and distributions have been paid by the Fund, the performance information for the Fund in the chart and table assumes reinvestment of the dividends and distributions. Sales charges are not reflected in the bar chart. If they were, returns would be less than those shown. However, the table includes all applicable fees and sales charges. If the Fund’s investment manager and its affiliates had not waived or reimbursed certain Fund expenses during these periods, the Fund’s returns would have been lower. Updated information about the Fund’s performance can be obtained by visiting www.blackrock.com/cash or can be obtained by phone at (800) 441-7762.</span></div>
The information below shows you how the Fund’s performance has varied year by year and provides some indication of the risks of investing in the Fund.
As with all such investments, past performance is not an indication of future results.
Sales charges are not reflected in the bar chart. If they were, returns would be less than those shown.
However, the table includes all applicable fees and sales charges.
www.blackrock.com/cash
(800) 441-7762
Investor A Shares ANNUAL TOTAL RETURNS BlackRock Summit Cash Reserves Fund As of 12/31
<div style="margin-top: 6pt;"><span style="color: #000000; font-family: arial; font-size: 9.30pt;">During the ten-year period shown in the bar chart, the highest return for a quarter was 1.26% (quarter ended December 31, 2023) and the lowest return for a quarter was 0.00% (quarter ended March 31, 2017). The year-to-date return as of June 30, 2026 was 1.64%.</span><span style="color: #000000; font-family: arial; font-size: 1pt; line-height: 0.93pt;"> </span></div>
highest return
0.0126
2023-12-31
lowest return
0.0000
2017-03-31
year-to-date return
2026-06-30
0.0164
For the periods ended 12/31/25Average Annual Total Returns
0.0393
0.0295
0.0178
0.0216
0.0240
0.0118
0.0393
0.0295
0.0177
<div style="margin-top: 12pt;"><span style="color: #000000; font-family: arial; font-size: 9.30pt;">To obtain the Fund’s current 7-day yield, call (800) 441-7762 or visit the Fund’s website at www.blackrock.com/cash.</span></div>
(800) 441-7762
As described in the “Management of the Fund” section of the Fund’s prospectus beginning on page 31, BlackRock has contractually agreed to waive and/or reimburse fees or expenses in order to limit Total Annual Fund Operating Expenses After Fee Waivers and/or Expense Reimbursements (excluding Dividend Expense, Interest Expense, Acquired Fund Fees and Expenses and certain other Fund expenses) to 0.42% (for Investor A Shares and Institutional Shares) and 1.17% (for Investor C Shares) of average daily net assets through June 30, 2028. The agreement may be terminated upon 90 days’ notice by a majority of the non-interested trustees of the Trust or by a vote of a majority of the outstanding voting securities of the Fund.
These expense figures do not reflect the imposition of the CDSC which may be deducted upon the redemption of Investor A Shares of the Fund received in an exchange transaction for Investor A Shares of an Investor A Load-Waived BlackRock Fund as described in the applicable prospectuses. No CDSC is deducted upon the redemption of Investor A Shares of the Fund that are not acquired by exchange.
Reflects assessment of applicable CDSC assuming Investor C Shares were acquired by exchange from a Non-Money Market BlackRock Fund immediately after purchase of shares from such other fund.
There is no contingent deferred sales charge (“CDSC”) on Investor A Shares purchased directly. However, a CDSC of up to 1.00% may apply to certain redemptions of the Fund’s Investor A Shares purchased in an exchange transaction for Investor A Shares of a fund advised by BlackRock or its affiliates where no initial sales charge was paid at the time of purchase of such fund (each, an “Investor A Load-Waived BlackRock Fund”) as part of an investment of $1,000,000 (lesser amounts may apply depending on the Investor A Load-Waived BlackRock Fund) or more. The Investor A Shares CDSC is only charged upon redemptions of Investor A Shares within 18 months after you originally acquired such Investor A Shares of the Investor A Load-Waived BlackRock Fund (a shorter holding period may apply depending on the Investor A Load-Waived BlackRock Fund), unless you qualify for a waiver. There is no CDSC charged on redemptions if you have owned your Investor A Shares for more than 18 months (or for a shorter holding period, as applicable) as measured from your original purchase of Investor A Shares that you exchanged into Investor A Shares of the Fund or if you purchase Investor A Shares of the Fund not through an exchange.
Since all Investor C Shares must be purchased in an exchange transaction for Investor C Shares of a non-money market fund advised by BlackRock or its affiliates (each a “Non-Money Market BlackRock Fund”), a CDSC of 1.00% may apply to certain redemptions of the Fund’s Investor C Shares. The Investor C Shares CDSC is only charged upon redemptions of Investor C Shares within one year after you originally acquired the Investor C Shares of the Non-Money Market BlackRock Fund, unless you qualify for a waiver. There is no CDSC charged on redemptions if you have owned your Investor C Shares for more than one year (as measured from your original purchase of Investor C Shares that you exchanged into Investor C Shares of the Fund).