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tbit:Russell1000GrowthIndexTotalReturnMember 2025-01-01 2025-12-31 0000816153 tbit:Russell1000GrowthIndexTotalReturnMember 2021-01-01 2025-12-31 0000816153 tbit:Russell1000GrowthIndexTotalReturnMember 2016-01-01 2025-12-31 0000816153 tbit:Russell2500GrowthIndexTotalReturnMember 2025-01-01 2025-12-31 0000816153 tbit:Russell2500GrowthIndexTotalReturnMember 2021-01-01 2025-12-31 0000816153 tbit:Russell2500GrowthIndexTotalReturnMember 2016-01-01 2025-12-31 iso4217:USD pure false 485BPOS 0000816153 2026-03-27 N-1A THORNBURG INVESTMENT TRUST 2026-03-27 American Opportunities Fund Investment Goal The Fund seeks long-term capital appreciation by investing in equity and debt securities of all types. Fees and Expenses of the Fund This table describes the fees and expenses that you may pay if you buy and hold ETF Class shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment) <div id="xdx_A81_eoef--AnnualFundOperatingExpensesTableTextBlock_zqWKZO8sHPLi"></div> <table cellpadding="0" cellspacing="0" id="xdx_A50_dU_zwcNXgoVXiS9" style="font: 10pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse" summary="xdx: Disclosure - Annual Fund Operating Expenses"> <tr style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom"> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; width: 50%"> </td> <td id="xdx_49A_20260327__20260327__oef--ClassAxis__custom--C000272858Member_zH4hBlzmWNe7" style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; width: 50%; background-color: #234B8D; text-align: center">ETF Class Shares</td></tr> <tr id="xdx_408_eoef--ManagementFeesOverAssets_dp_zlLIdNJsAki1" style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom; background-color: #E9EDF3"> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt">Management Fees1</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; text-align: center">0.79%</td></tr> <tr id="xdx_40E_eoef--OtherExpensesOverAssets_dp_zdMyrMWNuQod" style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom"> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt">Other Expenses2</td> <td style="border-bottom: #4F81BD 1.5pt solid; font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; text-align: center">0.14%</td></tr> <tr id="xdx_40C_eoef--ExpensesOverAssets_dp_znSg1QP6hwhc" style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom; background-color: #DBE5F1"> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt">Total Annual Fund Operating Expenses</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; text-align: center">0.93%</td></tr> <tr id="xdx_401_eoef--FeeWaiverOrReimbursementOverAssets_dp_z0F2HexmjM1" style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom"> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt">Fee Waiver/Expense Reimbursement3</td> <td style="border-bottom: #4F81BD 1.5pt solid; font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; text-align: center">-0.14%</td></tr> <tr id="xdx_401_eoef--NetExpensesOverAssets_dp_z0EprILyS741" style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom; background-color: #DBE5F1"> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt">Total Annual Fund Operating Expenses After Fee Waiver/Expense Reimbursement</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; text-align: center">0.79%</td></tr> </table> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; width: 100%"><tr style="vertical-align: top; text-align: justify"> <td style="text-align: right; width: 15pt">1</td><td style="width: 5pt; text-align: left"></td><td id="xdx_F1F_znB2bHIfTGmf" style="text-align: justify">Management fees have been restated to reflect contractual changes to the management fees paid by the Fund.</td> </tr></table> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0; margin-bottom: 6pt; width: 100%"><tr style="vertical-align: top; text-align: justify"> <td style="width: 15pt; text-align: right">2</td><td style="width: 5pt"></td><td style="text-align: justify">ETF Class shares of the Fund are new, so “Other Expenses" shown are based on anticipated fees and expenses for the first full fiscal year.</td> </tr></table> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0; margin-bottom: 6pt; width: 100%"><tr style="vertical-align: top; text-align: justify"> <td style="width: 15pt; text-align: right">3</td><td style="width: 5pt"></td><td style="text-align: justify">Thornburg Investment Management, Inc. (“Thornburg”) has contractually agreed to waive fees and reimburse expenses incurred by the Fund so that actual ETF Class expenses (excluding taxes, interest expenses, acquired fund fees and expenses, brokerage commissions, borrowing costs, expenses relating to short sales, and unusual expenses such as contingency fees or litigation costs) do not exceed 0.79%. The agreement to waive fees and reimburse expenses may be terminated by the Fund’s Trustees at any time, but may not be terminated by Thornburg before March 27, 2027, unless Thornburg ceases to be the investment advisor of the Fund prior to that date. Thornburg may recoup amounts waived or reimbursed during the Fund’s fiscal year if actual expenses fall below the expense cap during that same fiscal year.</td> </tr></table> 0.0079 0.0014 0.0093 -0.0014 0.0079 Management fees have been restated to reflect contractual changes to the management fees paid by the Fund. ETF Class shares of the Fund are new, so “Other Expenses" shown are based on anticipated fees and expenses for the first full fiscal year. March 27, 2027 Example. This Example is intended to help you compare the cost of investing in the Fund’s ETF Class shares with the cost of investing in other funds. The Example assumes that you invest $10,000 in the Fund’s ETF Class shares for the time periods indicated and then sell all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year, dividends and distributions are reinvested, and that the Fund’s operating expenses with respect to ETF Class shares remain the same. Although your actual costs may be higher or lower, based on these assumptions (and giving effect to fee waivers and expense reimbursements in the first year), your costs would be: <div id="xdx_A8A_eoef--ExpenseExampleWithRedemptionTableTextBlock_zkqlcrwMfXte"></div> <table cellpadding="0" cellspacing="0" id="xdx_A57_dU_zOdqZ53OeFRc" style="font: 10pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse" summary="xdx: Disclosure - Expense Example"> <tr style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom"> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt"> </td> <td id="xdx_48E_eoef--ExpenseExampleYear01_zdEUBdY3uCgl" style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; background-color: #234B8D; text-align: center">1 Year</td> <td id="xdx_482_eoef--ExpenseExampleYear03_zCn5zfC2lZx4" style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; background-color: #234B8D; text-align: center">3 Years</td> <td id="xdx_488_eoef--ExpenseExampleYear05_zsyWbR4sUed9" style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; background-color: #234B8D; text-align: center">5 Years</td> <td id="xdx_485_eoef--ExpenseExampleYear10_zLClBEWowruh" style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; background-color: #234B8D; text-align: center">10 Years</td></tr> <tr id="xdx_414_20260327__20260327__oef--ClassAxis__custom--C000272858Member_zFMJk64iYZ02" style="font: 10pt Times New Roman, Times, Serif; background-color: #E9EDF3"> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: bottom">ETF Class Shares</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: right">$81</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: right">$282</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: right">$501</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: right">$1,130</td></tr> </table> 81 282 501 1130 Portfolio Turnover. The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over”) its portfolio. A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in Annual Fund Operating Expenses or in the Example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 23.05% of the average value of its portfolio. 0.2305 Principal Investment Strategies The Fund expects to invest primarily in domestic equity securities (primarily common stocks) using the value criteria described below. However, the Fund may own a variety of securities, including foreign equity securities, partnership interests and foreign and domestic debt obligations which, in the opinion of the Fund’s investment advisor, Thornburg, offer prospects for meeting the Fund’s investment goals. Under normal conditions, the Fund will invest at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in equity investments that are tied economically to the United States. Thornburg intends to invest on an opportunistic basis where the Fund’s portfolio managers believe a company’s intrinsic value is not recognized by the marketplace. The Fund seeks to identify value in a broad or different context by investing in a diversified portfolio of stocks the Fund categorizes as basic values, consistent earners or emerging franchises, when the portfolio managers believe these issues are priced below Thornburg’s assessment of intrinsic value. The relative proportions of securities invested in each of those categories will vary over time. The Fund seeks to invest in promising companies, and may invest in stocks subject to unfavorable market perceptions of the company or industry fundamentals. The Fund may invest in companies of any size, but expects to invest primarily in large capitalization publicly traded companies. The Fund’s investments are determined by individual issuer and industry analysis. Investment decisions may be based on a variety of factors, including, without limitation, economic developments, outlooks for securities markets, interest rates and inflation, the supply and demand for securities, and analysis of specific issuers. The Fund categorizes its equity investments in the following three categories: Basic Value: Companies generally operating in mature or cyclical industries and which generally exhibit more economic sensitivity and/or higher volatility in earnings and cash flow. Consistent Earner: Companies which generally exhibit predictable growth, profitability, cash flow and/or dividends. Emerging Franchise: Companies with the potential to grow at an above average rate because of a product or service that is establishing a new market and/or taking share from existing participants. Inclusion of any investment in any of the three described categories represents the opinion of Thornburg concerning the characteristics and prospects of the investment. There is no assurance that any company selected for investment will, once categorized in one of the three described investment categories, continue to have the positive characteristics or fulfill the expectations that Thornburg had for the company when it was selected for investment, and any such company may not grow or may decline in earnings and size. The Fund may sell an investment if Thornburg has identified a better investment opportunity, in response to changes in the conditions or business of the investment’s issuer or changes in overall market conditions, if Thornburg has a target price for the investment and that target price has been achieved, or if, in Thornburg’s opinion, the investment no longer serves to achieve the Fund’s investment goals. Debt obligations may be considered for investment if Thornburg believes them to be more attractive than equity alternatives, or to manage risk. The Fund may purchase debt obligations of any maturity and of any credit quality, including “high yield” or “junk” bonds. There is no minimum credit quality or rating of debt obligation the Fund may purchase. The Fund’s policy of investing, under normal conditions, at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in equity investments that are tied economically to the United States may be changed by the Fund’s Trustees without a shareholder vote upon 60 days’ notice to shareholders. The Fund considers an equity investment to be “tied economically” to the United States if, at the time of purchase, Thornburg believes the issuer: (i) is organized under the laws of the United States or under the laws of a state within the United States or maintains a principal place of business in the United States; (ii) is traded principally in the United States; (iii) has or will derive at least 50% of its profits, revenues, sales, or income from goods produced or sold, investments made, or services performed in the United States, or has at least 50% of its assets in the United States, even if it also has significant economic exposures to countries other than the United States; or (iv) is a component of any unaffiliated index intended to represent all or a segment of the United States equity markets. The application of these factors is inevitably complex and subjective. Companies may be determined to be tied economically to the United States even if it may be economically tied to a number of other countries. The Fund's ETF Class operates as an actively managed exchange-traded fund (“ETF”). Under normal conditions, the Fund will invest at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in equity investments that are tied economically to the United States. An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. Accordingly, the loss of money is a risk of investing in the Fund. <p id="xdx_A88_eoef--RiskTextBlock_hoef--RiskAxis__us-gaap--CreditRiskMember_zA3zGMcn3IU8" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; margin-left: 0; text-align: justify">Credit Risk – The inability of an issuer to pay principal and interest on its debt obligations when due, or the downgrading of an issuer’s debt obligations by ratings agencies, may adversely affect the market’s perceptions of the issuer’s financial strength and may therefore result in declines in the issuer’s stock price. <p id="xdx_A8D_eoef--RiskTextBlock_hoef--RiskAxis__custom--CybersecurityAndOperationalRiskMember_zncE7wi7QSxj" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; margin-left: 0; text-align: justify">Cybersecurity and Operational Risk - Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. <p id="xdx_A83_eoef--RiskTextBlock_hoef--RiskAxis__custom--DepositaryReceiptsRiskMember_znm1jVv2YvPc" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; margin-left: 0; text-align: justify">Depositary Receipts Risk – An investment in American Depositary Receipts (“ADRs”), European Depositary Receipts (“EDRs”) or Global Depositary Receipts (“GDRs”) is an alternative to the purchase of the underlying securities in their national markets and/or currencies. However, ADRs, EDRs, and GDRs remain subject to many of the risks associated with investing directly in foreign securities, including the political and economic risks associated with the underlying issuer’s country. Certain countries may limit the ability to convert a depositary receipt into the underlying foreign security and vice versa, which may cause the securities of the foreign company to trade at a discount or premium to the market price of the related depositary receipts. Moreover, EDRs and GDRs can involve currency risk since, unlike ADRs, they may not be U.S. dollar denominated. <p id="xdx_A8A_eoef--RiskTextBlock_hoef--RiskAxis__custom--EquityRiskMember_zyxMilXuIEG5" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; margin-left: 0; text-align: justify">Equity Risk - The value of the Fund’s equity investments may fluctuate significantly over time in response to factors affecting individual issuers, particular industries, or the market as a whole. Additionally, common stock ranks below preferred stock and debt securities in claims for dividends and for assets of a company in a liquidation or bankruptcy. <p id="xdx_A80_eoef--RiskTextBlock_hoef--RiskAxis__custom--ETFStructureRisksMember_z6yBOc6a3K1k" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; margin-left: 0; text-align: justify">ETF Structure Risks - The Fund’s ETF Class shares operate as an ETF and are subject to risks related to exchange trading, including: <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0; margin-bottom: 0; width: 100%"><tr style="vertical-align: top; text-align: justify"> <td style="width: 0.25in"></td><td style="width: 0.25in; text-align: left">■</td><td style="text-align: justify">The Fund’s ETF Class shares are listed for trading on Nasdaq Stock Market, LLC (the “Exchange”) and are bought and sold on the secondary market at market prices. Although it is expected that the market price of the Fund’s ETF Class shares will typically approximate the Fund’s NAV, there may be times when the market price reflects a significant premium or discount to NAV.</td> </tr></table> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0; margin-bottom: 0; width: 100%"><tr style="vertical-align: top; text-align: justify"> <td style="width: 0.25in"></td><td style="width: 0.25in; text-align: left">■</td><td style="text-align: justify">Although the Fund’s ETF Class shares are listed on the Exchange, it is possible that an active trading market in the Fund’s ETF Class shares may not be maintained. In stressed market conditions, the market for the Fund’s ETF Class shares may become less liquid in response to deteriorating liquidity in the markets for the Fund’s underlying portfolio holdings, which could lead to wider bid/ask spreads and differences in the market price of the Fund’s ETF Class shares and the underlying value of those shares.</td> </tr></table> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0; margin-bottom: 0; width: 100%"><tr style="vertical-align: top; text-align: justify"> <td style="width: 0.25in"></td><td style="width: 0.25in; text-align: left">■</td><td style="text-align: justify">The Fund’s ETF Class shares could potentially face trading halts and/or delisting from the Exchange. This risk is heightened in times of market stress, including at both the Fund ETF Class share level and at the Fund holdings level.</td> </tr></table> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0; margin-bottom: 0; width: 100%"><tr style="vertical-align: top; text-align: justify"> <td style="width: 0.25in"></td><td style="width: 0.25in; text-align: left">■</td><td style="text-align: justify">Only an authorized participant (an “Authorized Participant”) may engage in creation or redemption transactions directly with the Fund with respect to ETF Class shares, and none of those Authorized Participants is obligated to engage in creation and/or redemption transactions. The Fund has a limited number of institutions that may act as Authorized Participants on an agency basis (i.e., on behalf of other market participants). In addition, to the extent that securities held by the Fund are traded outside a collateralized settlement system, Authorized Participants may be required to post collateral on certain trades on an agency basis (on behalf of other market participants), which only a limited number of Authorized Participants may be able to do. To the extent that Authorized Participants exit the business or are unable to proceed with creation or redemption orders with respect to the ETF Class shares of the Fund and no other Authorized Participant is able to step forward to create or redeem creation units (“Creation Units”), the Fund’s ETF Class shares may be more likely to trade at a premium or discount to NAV and possibly face trading halts or delisting.</td> </tr></table> <p id="xdx_A8F_eoef--RiskTextBlock_hoef--RiskAxis__custom--ForeignInvestmentRiskMember_zq6xvPR55zth" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; margin-left: 0; text-align: justify">Foreign Investment Risk - Investments in securities of foreign issuers may involve risks including adverse fluctuations in currency exchange rates, political instability, confiscations, taxes or restrictions on currency exchange, difficulty in selling foreign investments, and reduced legal protection. These risks may be more pronounced for investments in countries that are less diversified and where communications, transportation and economic infrastructures are less developed. Such countries ordinarily have less established legal, political, business and social frameworks. At times the prices of equity securities of foreign issuers may be extremely volatile. <p id="xdx_A84_eoef--RiskTextBlock_hoef--RiskAxis__custom--LiquidityRiskMember_z9Urv0acZlOi" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; margin-left: 0; text-align: justify">Liquidity Risk - Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell some or all of its investments promptly, or may only be able to sell investments at less than desired prices. <p id="xdx_A8A_eoef--RiskTextBlock_hoef--RiskAxis__custom--ManagementRiskMember_z43c9SfTCSZ4" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; margin-left: 0; text-align: justify">Management Risk - The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. <p id="xdx_A80_eoef--RiskTextBlock_hoef--RiskAxis__custom--MarketAndEconomicRiskMember_ztIpdVaGwq69" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; margin-left: 0; text-align: justify">Market and Economic Risk - The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. The value of a security may change in response to developments affecting entire economies, markets or industries, including changes in interest rates, political and legal developments, and general market volatility. <p id="xdx_A86_eoef--RiskTextBlock_hoef--RiskAxis__custom--RisksAffectingSpecificCountriesorRegionsMember_zyGmw28Ej6kc" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; margin-left: 0; text-align: justify">Risks Affecting Specific Countries or Regions – If a significant portion of the Fund’s assets is invested in issuers that are economically exposed to one country or region, the Fund’s share value may be more susceptible to the conditions and developments in that country or region, and potentially more volatile than the share value of a more geographically diversified fund. A specific country or region could also be adversely affected by conditions or developments arising in other countries. For example, the U.S. government could take actions to prohibit or restrict individuals or companies within the U.S. from purchasing or holding the shares of issuers in another country, which may limit the Fund’s ability to invest in that country or cause the Fund to have to sell investments in that country at less than desired prices. The nature and degree of the risks affecting a given country or region, and the extent of the Fund’s exposure to any such country or region, is expected to vary over time. <p id="xdx_A8B_eoef--RiskTextBlock_hoef--RiskAxis__custom--RisksAffectingSpecificIssuersMember_zCQpw9K90uE4" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; margin-left: 0; text-align: justify">Risks Affecting Specific Issuers - The value of a security may decline in response to developments affecting the specific issuer of the security, even if the overall industry or economy is unaffected. These developments may include a variety of factors, including but not limited to management issues or other corporate disruption, a decline in revenues or profitability, an increase in costs, or an adverse effect on the issuer’s competitive position. Past Performance of the Fund The following information provides some indication of the risks of investing in the American Opportunities Fund by showing how the investment results of the Fund’s Class I shares varied from year to year. Because the Fund’s ETF Class shares had not commenced operations as of the date of this Prospectus, the bar chart shows how the annual total returns for Class I shares have been different in each full year shown. Class I shares are a mutual fund class of shares of the Fund and are not offered in this Prospectus. Class I shares would have substantially similar annual returns to ETF Class shares because the shares are invested in the same portfolio of securities and the annual returns at NAV (assuming ETF Class shares are bought and sold without any premium or discount) would differ only to the extent that Class I shares do not have the same expenses as the ETF Class shares (ETF Class shares have lower total expenses than Class I shares). Performance information for ETF Class shares will be provided after such shares have one full calendar year of performance. The average annual total return figures compare Class I share performance to the S&P 500 Index—Total Return, a broad-based securities market index that represents the overall applicable market in which the Fund invests, and the Russell 1000 Value Index—Total Return, an additional index that represents the market sectors which Thornburg believes are more representative of the Fund’s investment universe. These indexes are not actively managed and are not available for direct investment. As of March 23, 2026, the Fund no longer compares its returns to the Russell 3000 Index—Total Return or Russell 2500 Index—Total Return because the current indices better reflect the Fund’s current investment universe (as described below). The performance information shown below is as of the calendar year ended December 31, 2025. Before March 23, 2026, the Fund was managed with a different principal investment strategy under the name “Thornburg Small/Mid Cap Core Fund” and may have achieved different performance results under its current principal investment strategy from the performance shown for periods before that date. Past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. The bar charts and performance tables assume reinvestment of dividends and distributions. Updated performance information may be obtained on the Thornburg website at Thornburg.com or by calling 1-800-847-0200. The following information provides some indication of the risks of investing in the American Opportunities Fund by showing how the investment results of the Fund’s Class I shares varied from year to year. Past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Thornburg.com 1-800-847-0200 Annual Total Returns - Class I Shares <div id="xdx_A88_eoef--BarChartTableTextBlock_z6wMnSfPwgpj"></div> <table cellpadding="0" cellspacing="0" id="xdx_A5C_zqdRn17WUv75" style="font: 10pt Times New Roman, Times, Serif; display: none; visibility: hidden; border-collapse: collapse; width: 100%" summary="xdx: Disclosure - Annual Total Returns"> <tr style="vertical-align: top; text-align: left"> <td style="width: 50%"> </td> <td id="xdx_480_eoef--AnnlRtrPct_dp_hoef--ClassAxis__custom--C000032364Member_zK9FM8oj56ci" style="width: 50%"></td></tr> <tr id="xdx_413_20160101__20161231_z931g61LzTWd" style="vertical-align: top; text-align: left"> <td>2016</td> <td>7.03%</td></tr> <tr id="xdx_41B_20170101__20171231_zo8xC8iJGXC9" style="vertical-align: top; text-align: left"> <td>2017</td> <td>23.81%</td></tr> <tr id="xdx_419_20180101__20181231_zVbacipoOQ15" style="vertical-align: top; text-align: left"> <td>2018</td> <td>-9.39%</td></tr> <tr id="xdx_411_20190101__20191231_zXoUWJPqWXM8" style="vertical-align: top; text-align: left"> <td>2019</td> <td>29.31%</td></tr> <tr id="xdx_41E_20200101__20201231_zVwVu2f1Zzsj" style="vertical-align: top; text-align: left"> <td>2020</td> <td>12.10%</td></tr> <tr id="xdx_41C_20210101__20211231_zxrVeGdDtUVj" style="vertical-align: top; text-align: left"> <td>2021</td> <td>14.18%</td></tr> <tr id="xdx_412_20220101__20221231_z10UwNc3Uyt7" style="vertical-align: top; text-align: left"> <td>2022</td> <td>-19.19%</td></tr> <tr id="xdx_410_20230101__20231231_zY9bUOYAiCVa" style="vertical-align: top; text-align: left"> <td>2023</td> <td>13.61%</td></tr> <tr id="xdx_413_20240101__20241231_zPcaJkUtS2n3" style="vertical-align: top; text-align: left"> <td>2024</td> <td>19.92%</td></tr> <tr id="xdx_41E_20250101__20251231_za3q02MFDYx4" style="vertical-align: top; text-align: left"> <td>2025</td> <td>-0.50%</td></tr> </table> <img alt="" src="thornburgchart002.jpg" style="height: 299px; width: 500px"/> 0.0703 0.2381 -0.0939 0.2931 0.1210 0.1418 -0.1919 0.1361 0.1992 -0.0050 <div id="xdx_A8A_eoef--BarChartClosingTextBlock_zynTjY49rxfa"></div> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse"> <tr style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom"> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt"> </td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; background-color: #234B8D; text-align: center">Total Returns</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; background-color: #234B8D; text-align: center">Quarter ended</td></tr> <tr style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom; background-color: #E9EDF3"> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt">Highest Quarterly Results</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; text-align: center">18.99%</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; text-align: center">6/30/2020</td></tr> <tr style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom"> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt">Lowest Quarterly Results</td> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; text-align: center">-26.24%</td> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; text-align: center">3/31/2020</td></tr> </table> Highest Quarterly Results 0.1899 2020-06-30 Lowest Quarterly Results -0.2624 2020-03-31 Average Annual Total Returns (periods ended 12-31-25) <div id="xdx_A85_eoef--PerformanceTableTextBlock_za0GcfzMuk03"></div> <table cellpadding="0" cellspacing="0" id="xdx_A52_dU_zEtvVv1n0EN3" style="font: 10pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse" summary="xdx: Disclosure - Average Annual Total Returns"> <tr style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom"> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt">CLASS I SHARES</td> <td id="xdx_495_20250101__20251231_zokVbnxB8E4l" style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; background-color: #234B8D; text-align: center">1 YEAR</td> <td id="xdx_491_20210101__20251231_zgpk1cdCBd6h" style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; background-color: #234B8D; text-align: center">5 YEARS</td> <td id="xdx_491_20160101__20251231_zZn7MDwbnyoi" style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; background-color: #234B8D; text-align: center">10 YEARS</td></tr> <tr id="xdx_403_eoef--AvgAnnlRtrPct_dp_hoef--ClassAxis__custom--C000032364Member_zXhThvX0qIWa" style="font: 10pt Times New Roman, Times, Serif; background-color: #E9EDF3"> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: bottom">Return Before Taxes</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: bottom; text-align: center">-0.50%</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: center">4.58%</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: center">8.09%</td></tr> <tr id="xdx_406_eoef--AvgAnnlRtrPct_dp_hoef--ClassAxis__custom--C000032364Member__oef--PerformanceMeasureAxis__oef--AfterTaxesOnDistributionsMember_zmsnUaJfjdjl" style="font: 10pt Times New Roman, Times, Serif"> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: bottom">Return After Taxes on Distributions</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: bottom; text-align: center">-0.50%</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: center">2.91%</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: center">7.09%</td></tr> <tr id="xdx_402_eoef--AvgAnnlRtrPct_dp_hoef--ClassAxis__custom--C000032364Member__oef--PerformanceMeasureAxis__oef--AfterTaxesOnDistributionsAndSalesMember_z3JIHsiQk4tf" style="font: 10pt Times New Roman, Times, Serif; background-color: #E9EDF3"> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: bottom">Return After Taxes on Distributions and Sale of Fund Shares</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: center">-0.30%</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: center">3.17%</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: center">6.30%</td></tr> <tr id="xdx_409_eoef--AvgAnnlRtrPct_dp_hoef--PerformanceMeasureAxis__custom--SAndP500IndexMember_zaAlrhlgtaOb" style="font: 10pt Times New Roman, Times, Serif"> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: bottom">S&P 500 Index—Total Return (reflects no deduction for fees, expenses, or taxes)</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: center">17.88%</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: center">14.42%</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: center">14.82%</td></tr> <tr id="xdx_402_eoef--AvgAnnlRtrPct_dp_hoef--PerformanceMeasureAxis__custom--Russell1000ValueIndexMember_zq3TjW5NxRej" style="font: 10pt Times New Roman, Times, Serif; background-color: #E9EDF3"> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: bottom">Russell 1000 Value Index—Total Return (reflects no deduction for fees, expenses, or taxes)</td> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: center">15.91%</td> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: center">11.33%</td> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: center">10.53%</td></tr> <tr id="xdx_409_eoef--AvgAnnlRtrPct_dp_hoef--PerformanceMeasureAxis__custom--Russell3000IndexTotalReturnMember_zvbcIiwUvuU9" style="font: 10pt Times New Roman, Times, Serif"> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: bottom">Russell 3000 Index-Total Return (reflects no deduction for fees, expenses, or taxes)</td> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: center">17.15%</td> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: center">13.15%</td> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: center">14.29%</td></tr> <tr id="xdx_408_eoef--AvgAnnlRtrPct_dp_hoef--PerformanceMeasureAxis__custom--Russell2500IndexTotalReturnMember_zFEVuf3wmJIa" style="font: 10pt Times New Roman, Times, Serif; background-color: #E9EDF3"> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: bottom">Russell 2500 Index-Total Return (reflects no deduction for fees, expenses, or taxes)</td> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: center">11.91%</td> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: center">7.26%</td> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: center">10.40%</td></tr> </table> -0.0050 0.0458 0.0809 -0.0050 0.0291 0.0709 -0.0030 0.0317 0.0630 (reflects no deduction for fees, expenses, or taxes) 0.1788 0.1442 0.1482 (reflects no deduction for fees, expenses, or taxes) 0.1591 0.1133 0.1053 (reflects no deduction for fees, expenses, or taxes) 0.1715 0.1315 0.1429 (reflects no deduction for fees, expenses, or taxes) 0.1191 0.0726 0.1040 After-tax returns are calculated using the highest historical individual federal marginal income tax rates, and do not reflect state or local income taxes. Actual after-tax returns depend on an investor’s own tax situation and may differ from the returns shown, and after-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. The after-tax returns shown relate only to Class I shares, and after-tax returns for other share classes will vary. The performance information shown above may include gains attributable to the Fund’s investments in shares of companies through initial public offerings (“IPOs”). There can be no assurance that the Fund will have continued access to profitable IPOs and, as the Fund’s assets grow, the impact of the Fund’s investment in IPOs on the performance of the Fund may decline. After-tax returns are calculated using the highest historical individual federal marginal income tax rates, and do not reflect state or local income taxes. Actual after-tax returns depend on an investor’s own tax situation and may differ from the returns shown, and after-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. The after-tax returns shown relate only to Class I shares, and after-tax returns for other share classes will vary. Focus Growth Fund Investment Goal The Fund seeks long-term growth of capital by investing in equity securities selected for their growth potential. Fees and Expenses of the Fund This table describes the fees and expenses that you may pay if you buy and hold ETF Class shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment) <div id="xdx_A8F_eoef--AnnualFundOperatingExpensesTableTextBlock_zw0JAJTv9xa1"></div> <table cellpadding="0" cellspacing="0" id="xdx_A59_dU_z20ZQuykNYjg" style="font: 10pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse" summary="xdx: Disclosure - Annual Fund Operating Expenses"> <tr style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom"> <td style="font: 10pt Times New Roman, Times, Serif"> </td> <td id="xdx_49D_20260327__20260327__oef--ClassAxis__custom--C000272859Member_zcmAZqGFRMde" style="font: 10pt Times New Roman, Times, Serif; width: 55%; background-color: #234B8D; text-align: center">ETF Class Shares</td></tr> <tr id="xdx_408_eoef--ManagementFeesOverAssets_dp_zM5S9nSaz0Vl" style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom; background-color: #DBE5F1"> <td style="font: 10pt Times New Roman, Times, Serif">Management Fees1</td> <td style="font: 10pt Times New Roman, Times, Serif; text-align: center">0.79%</td></tr> <tr id="xdx_40E_eoef--OtherExpensesOverAssets_dp_z41zhb7vrjE2" style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom; background-color: white"> <td style="font: 10pt Times New Roman, Times, Serif">Other Expenses2</td> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; text-align: center">0.19%</td></tr> <tr id="xdx_40C_eoef--ExpensesOverAssets_dp_zqZ7esuFTOHa" style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom; background-color: #DBE5F1"> <td style="font: 10pt Times New Roman, Times, Serif">Total Annual Fund Operating Expenses</td> <td style="font: 10pt Times New Roman, Times, Serif; text-align: center">0.98%</td></tr> <tr id="xdx_401_eoef--FeeWaiverOrReimbursementOverAssets_dp_zSCt1049Vgxh" style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom"> <td style="font: 10pt Times New Roman, Times, Serif">Fee Waiver/Expense Reimbursement3</td> <td style="font: 10pt Times New Roman, Times, Serif; text-align: center">-0.19%</td></tr> <tr id="xdx_405_eoef--NetExpensesOverAssets_dp_zHKYTQKKFGef" style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom; background-color: #DBE5F1"> <td style="font: 10pt Times New Roman, Times, Serif">Total Annual Fund Operating Expenses After Fee Waiver/Expense Reimbursement</td> <td style="font: 10pt Times New Roman, Times, Serif; text-align: center">0.79%</td></tr> </table> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0; margin-bottom: 6pt; width: 100%"><tr style="vertical-align: top; text-align: justify"> <td style="text-align: right; width: 15pt">1</td><td style="width: 5pt; text-align: left"></td><td id="xdx_F1D_zCmrTlOtTQ8i" style="text-align: justify">Management fees have been restated to reflect contractual changes to the management fees paid by the Fund.</td> </tr></table> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0; margin-bottom: 6pt; width: 100%"><tr style="vertical-align: top; text-align: justify"> <td style="width: 15pt; text-align: right">2</td><td style="width: 5pt"></td><td style="text-align: justify">ETF Class shares of the Fund are new, so “Other Expenses" shown are based on anticipated fees and expenses for the first full fiscal year.</td> </tr></table> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0; margin-bottom: 6pt; width: 100%"><tr style="vertical-align: top; text-align: justify"> <td style="width: 15pt; text-align: right">3</td><td style="width: 5pt"></td><td style="text-align: justify">Thornburg Investment Management, Inc. (“Thornburg”) has contractually agreed to waive fees and reimburse expenses incurred by the Fund so that actual ETF Class expenses (excluding taxes, interest expenses, acquired fund fees and expenses, brokerage commissions, borrowing costs, expenses relating to short sales, and unusual expenses such as contingency fees or litigation costs) do not exceed 0.79%. The agreement to waive fees and reimburse expenses may be terminated by the Fund’s Trustees at any time, but may not be terminated by Thornburg before March 27, 2027, unless Thornburg ceases to be the investment advisor of the Fund prior to that date. Thornburg may recoup amounts waived or reimbursed during the Fund’s fiscal year if actual expenses fall below the expense cap during that same fiscal year.</td> </tr></table> 0.0079 0.0019 0.0098 -0.0019 0.0079 Management fees have been restated to reflect contractual changes to the management fees paid by the Fund. ETF Class shares of the Fund are new, so “Other Expenses" shown are based on anticipated fees and expenses for the first full fiscal year. March 27, 2027 Example. This Example is intended to help you compare the cost of investing in the Fund’s ETF Class shares with the cost of investing in other funds. The Example assumes that you invest $10,000 in the Fund’s ETF Class shares for the time periods indicated and then sell all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return each year, dividends and distributions are reinvested, and that the Fund’s operating expenses with respect to ETF Class shares remain the same. Although your actual costs may be higher or lower, based on these assumptions (and giving effect to fee waivers and expense reimbursements in the first year), your costs would be: <div id="xdx_A84_eoef--ExpenseExampleWithRedemptionTableTextBlock_zgCuqxARrj33"></div> <table cellpadding="0" cellspacing="0" id="xdx_A5C_dU_z4xaHuPSSHra" style="font: 10pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse" summary="xdx: Disclosure - Expense Example"> <tr style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom"> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt"> </td> <td id="xdx_48F_eoef--ExpenseExampleYear01_z5xjoKJfAyG8" style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; background-color: #234B8D; text-align: center">1 Year</td> <td id="xdx_48D_eoef--ExpenseExampleYear03_zoINeQ50bRZ" style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; background-color: #234B8D; text-align: center">3 Years</td> <td id="xdx_483_eoef--ExpenseExampleYear05_zIOJAV9WJT33" style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; background-color: #234B8D; text-align: center">5 Years</td> <td id="xdx_486_eoef--ExpenseExampleYear10_zrllejF05Kuk" style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; background-color: #234B8D; text-align: center">10 Years</td></tr> <tr id="xdx_410_20260327__20260327__oef--ClassAxis__custom--C000272859Member_z00iUHupQuVe" style="font: 10pt Times New Roman, Times, Serif; background-color: #E9EDF3"> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: bottom">ETF Class Shares</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: bottom; text-align: right">$81</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: right">$293</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: right">$523</td> <td style="font: 10pt Times New Roman, Times, Serif; padding: 2pt 5.4pt; vertical-align: top; text-align: right">$1,184</td></tr> </table> 81 293 523 1184 Portfolio Turnover. The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over”) its portfolio. A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Fund shares are held in a taxable account. These costs, which are not reflected in Annual Fund Operating Expenses or in the Example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 34.06% of the average value of its portfolio. 0.3406 Principal Investment Strategies Under normal conditions, the Fund invests at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in growth companies. The Fund currently considers a company to be a growth company if it meets any of the following criteria: <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; width: 100%; margin-top: 0pt; margin-bottom: 0pt"><tr style="font: 10pt Times New Roman, Times, Serif; vertical-align: top"> <td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in"></td><td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in">■</td><td style="font: 10pt Times New Roman, Times, Serif; text-align: justify">It is a constituent of the Russell 2500 Growth Index or any other unaffiliated index intended to represent a range of growth oriented companies or investments; or</td></tr></table> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; width: 100%; margin-top: 0pt; margin-bottom: 0pt"><tr style="font: 10pt Times New Roman, Times, Serif; vertical-align: top"> <td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in"></td><td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in">■</td><td style="font: 10pt Times New Roman, Times, Serif; text-align: justify">It has, over the last five years, grown its revenues or earnings per share at an average annual rate which exceeds the median growth rate of revenues or earnings per share, as applicable, for companies in the Russell 2500 Growth Index; or</td></tr></table> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; width: 100%; margin-top: 0pt; margin-bottom: 0pt"><tr style="font: 10pt Times New Roman, Times, Serif; vertical-align: top"> <td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in"></td><td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in">■</td><td style="font: 10pt Times New Roman, Times, Serif; text-align: justify">It is projected by consensus estimates as compiled by FactSet Research Systems (“FactSet”), over the next two years, to grow its revenues or earnings per share at an average annual rate which exceeds the median growth rate of revenues or earnings per share, as applicable, for companies in the Russell 2500 Growth Index. FactSet has no affiliation with the Fund or its investment advisor.</td></tr></table> The Fund expects to invest primarily in domestic equity securities (primarily common stocks). However, the Fund may own a variety of securities, including foreign equity securities. The Fund can invest in companies of any size, from larger, well-established companies to smaller, emerging growth companies. The Fund seeks to invest in a diversified portfolio of companies the Fund categorizes as growth industry leader, consistent grower or emerging growth, as described in more detail below. The relative proportions of securities invested in each of those categories will vary over time. Thornburg primarily takes a bottom-up, fundamental view in determining the attractiveness of individual securities and in making investment decisions. Among the specific factors considered by Thornburg in identifying securities for inclusion in the Fund are: <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; width: 100%; margin-top: 0pt; margin-bottom: 0pt"><tr style="font: 10pt Times New Roman, Times, Serif; vertical-align: top"> <td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in"></td><td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in">■</td><td style="font: 10pt Times New Roman, Times, Serif; text-align: justify">earnings growth potential</td></tr></table> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; width: 100%; margin-top: 0pt; margin-bottom: 0pt"><tr style="font: 10pt Times New Roman, Times, Serif; vertical-align: top"> <td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in"></td><td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in">■</td><td style="font: 10pt Times New Roman, Times, Serif; text-align: justify">durable business model</td></tr></table> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; width: 100%; margin-top: 0pt; margin-bottom: 0pt"><tr style="font: 10pt Times New Roman, Times, Serif; vertical-align: top"> <td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in"></td><td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in">■</td><td style="font: 10pt Times New Roman, Times, Serif; text-align: justify">industry growth potential</td></tr></table> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; width: 100%; margin-top: 0pt; margin-bottom: 0pt"><tr style="font: 10pt Times New Roman, Times, Serif; vertical-align: top"> <td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in"></td><td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in">■</td><td style="font: 10pt Times New Roman, Times, Serif; text-align: justify">innovation driving the potential to disrupt entrenched competitors</td></tr></table> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; width: 100%; margin-top: 0pt; margin-bottom: 0pt"><tr style="font: 10pt Times New Roman, Times, Serif; vertical-align: top"> <td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in"></td><td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in">■</td><td style="font: 10pt Times New Roman, Times, Serif; text-align: justify">intrinsic value appreciation potential</td></tr></table> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; width: 100%; margin-top: 0pt; margin-bottom: 0pt"><tr style="font: 10pt Times New Roman, Times, Serif; vertical-align: top"> <td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in"></td><td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in">■</td><td style="font: 10pt Times New Roman, Times, Serif; text-align: justify">potential size of addressable market</td></tr></table> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; width: 100%; margin-top: 0pt; margin-bottom: 0pt"><tr style="font: 10pt Times New Roman, Times, Serif; vertical-align: top"> <td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in"></td><td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in">■</td><td style="font: 10pt Times New Roman, Times, Serif; text-align: justify">management strength</td></tr></table> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; width: 100%; margin-top: 0pt; margin-bottom: 0pt"><tr style="font: 10pt Times New Roman, Times, Serif; vertical-align: top"> <td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in"></td><td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in">■</td><td style="font: 10pt Times New Roman, Times, Serif; text-align: justify">leverage</td></tr></table> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; width: 100%; margin-top: 0pt; margin-bottom: 0pt"><tr style="font: 10pt Times New Roman, Times, Serif; vertical-align: top"> <td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in"></td><td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in">■</td><td style="font: 10pt Times New Roman, Times, Serif; text-align: justify">return on invested capital</td></tr></table> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; width: 100%; margin-top: 0pt; margin-bottom: 0pt"><tr style="font: 10pt Times New Roman, Times, Serif; vertical-align: top"> <td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in"></td><td style="font: 10pt Times New Roman, Times, Serif; width: 0.25in">■</td><td style="font: 10pt Times New Roman, Times, Serif; text-align: justify">valuation metrics, including: price/earnings (“PE”) ratio; enterprise value/revenue ratio; PE/growth rate ratio, enterprise value/EBITDA (earnings before interest, taxes, depreciation and amortization) ratio; and free cash flow yield.</td></tr></table> The Fund categorizes its equity investments in the following three categories: Growth Industry Leader: Companies in this category often have leadership positions in growing markets. In some cases these companies may have dominant market share. These companies tend to be larger and more established. Consistent Grower: Companies in this category generally exhibit steady earnings or revenue growth, or both. These companies may have subscription or other recurring revenue profiles. Given their business models, these companies may outperform in weak markets. Emerging Growth: Companies often addressing a new market or carving out a niche in an existing market. Companies in this category may experience rapid growth, and tend to be smaller, earlier stage companies. These companies may exhibit high volatility. Inclusion of any investment in any of the three described categories represents Thornburg’s opinion concerning the characteristics and prospects of the investment. There is no assurance that any company selected for investment will, once categorized in one of the three described investment categories, continue to have the positive characteristics or fulfill the expectations that Thornburg had for the company when it was selected for investment, and any such company may not grow or may decline in earnings and size. The Fund’s investments are determined by individual issuer and industry analysis. Investment decisions may be based on a variety of factors, including, without limitation, domestic and international economic developments, outlooks for securities markets, interest rates and inflation, the supply and demand for securities, and analysis of specific issuers. In conjunction with individual issuer analysis, Thornburg may identify and invest at times with a greater emphasis in industries or economic sectors it expects to experience growth. The Fund does not have a strategy to invest in any particular industry or economic sectors, and its exposures to particular industries or economic sectors are expected to vary over time. The Fund may sell an investment if Thornburg has identified a better investment opportunity, in response to changes in the conditions or business of the investment’s issuer or changes in overall market conditions, if Thornburg has a target price for the investment and that target price has been achieved, or if, in Thornburg’s opinion, the investment no longer serves to achieve the Fund’s investment goals. Debt obligations, usually with associated equity features, occasionally will be considered for investment when Thornburg believes them to be more attractive than equity alternatives. The Fund may purchase debt obligations of any maturity and of any credit quality, including “high yield” or “junk” bonds. There is no minimum credit quality or rating of debt obligation the Fund may purchase. The Fund’s policy of investing at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in growth companies may be changed by the Fund’s Trustees without a shareholder vote upon 60 days’ notice to shareholders. Additionally, the Fund may change its definition of what constitutes a “growth company” at any time without advance notice to shareholders. The Fund's ETF Class operates as an actively managed exchange-traded fund (“ETF”). Under normal conditions, the Fund invests at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in growth companies. An investment in the Fund is not a deposit in any bank and is not insured or guaranteed by the Federal Deposit Insurance Corporation or any other governmental agency. Accordingly, the loss of money is a risk of investing in the Fund. <p id="xdx_A8F_eoef--RiskTextBlock_hoef--RiskAxis__us-gaap--CreditRiskMember_z1iY83nNFC43" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; margin-left: 0; text-align: justify">Credit Risk – The inability of an issuer to pay principal and interest on its debt obligations when due, or the downgrading of an issuer’s debt obligations by ratings agencies, may adversely affect the market’s perceptions of the issuer’s financial strength and may therefore result in declines in the issuer’s stock price. <p id="xdx_A82_eoef--RiskTextBlock_hoef--RiskAxis__custom--CybersecurityAndOperationalRiskMember_zXbTmoaUHQ0a" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; margin-left: 0; text-align: justify">Cybersecurity and Operational Risk - Operational failures, cyber-attacks or other disruptions that affect the Fund’s service providers, the Fund’s counterparties, other market participants or the issuers of securities held by the Fund may adversely affect the Fund and its shareholders, including by causing losses for the Fund or impairing Fund operations. The rapid development and increasingly widespread use of artificial intelligence, including machine learning technology and generative artificial intelligence such as ChatGPT, could exacerbate these risks. <p id="xdx_A89_eoef--RiskTextBlock_hoef--RiskAxis__custom--DepositaryReceiptsRiskMember_z02jL8dcnLkk" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; margin-left: 0; text-align: justify">Depositary Receipts Risk – An investment in American Depositary Receipts (“ADRs”), European Depositary Receipts (“EDRs”) or Global Depositary Receipts (“GDRs”) is an alternative to the purchase of the underlying securities in their national markets and/or currencies. However, ADRs, EDRs, and GDRs remain subject to many of the risks associated with investing directly in foreign securities, including the political and economic risks associated with the underlying issuer’s country. Certain countries may limit the ability to convert a depositary receipt into the underlying foreign security and vice versa, which may cause the securities of the foreign company to trade at a discount or premium to the market price of the related depositary receipts. Moreover, EDRs and GDRs can involve currency risk since, unlike ADRs, they may not be U.S. dollar denominated. <p id="xdx_A8C_eoef--RiskTextBlock_hoef--RiskAxis__custom--EquityRiskMember_zzLlHRVtldj6" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; margin-left: 0; text-align: justify">Equity Risk - The value of the Fund’s equity investments may fluctuate significantly over time in response to factors affecting individual issuers, particular industries, or the market as a whole. Additionally, common stock ranks below preferred stock and debt securities in claims for dividends and for assets of a company in a liquidation or bankruptcy. <p id="xdx_A89_eoef--RiskTextBlock_hoef--RiskAxis__custom--ETFStructureRisksMember_zhDoFxKw3U59" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; margin-left: 0; text-align: justify">ETF Structure Risks - The Fund’s ETF Class shares operate as an ETF and are subject to risks related to exchange trading, including: <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0; margin-bottom: 0; width: 100%"><tr style="vertical-align: top; text-align: justify"> <td style="width: 0.5in"></td><td style="width: 0.25in; text-align: left">■</td><td style="text-align: justify">The Fund’s ETF Class shares are listed for trading on Nasdaq Stock Market, LLC (the “Exchange”) and are bought and sold on the secondary market at market prices. Although it is expected that the market price of the Fund’s ETF Class shares will typically approximate the Fund’s NAV, there may be times when the market price reflects a significant premium or discount to NAV.</td> </tr></table> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0; margin-bottom: 0; width: 100%"><tr style="vertical-align: top; text-align: justify"> <td style="width: 0.5in"></td><td style="width: 0.25in; text-align: left">■</td><td style="text-align: justify">Although the Fund’s ETF Class shares are listed on the Exchange, it is possible that an active trading market in the Fund’s ETF Class shares may not be maintained. In stressed market conditions, the market for the Fund’s ETF Class shares may become less liquid in response to deteriorating liquidity in the markets for the Fund’s underlying portfolio holdings, which could lead to wider bid/ask spreads and differences in the market price of the Fund’s ETF Class shares and the underlying value of those shares.</td> </tr></table> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0; margin-bottom: 0; width: 100%"><tr style="vertical-align: top; text-align: justify"> <td style="width: 0.5in"></td><td style="width: 0.25in; text-align: left">■</td><td style="text-align: justify">The Fund’s ETF Class shares could potentially face trading halts and/or delisting from the Exchange. This risk is heightened in times of market stress, including at both the Fund ETF Class share level and at the Fund holdings level.</td> </tr></table> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0; margin-bottom: 0; width: 100%"><tr style="vertical-align: top; text-align: justify"> <td style="width: 0.5in"></td><td style="width: 0.25in; text-align: left">■</td><td style="text-align: justify">Only an authorized participant (an “Authorized Participant”) may engage in creation or redemption transactions directly with the Fund with respect to ETF Class shares, and none of those Authorized Participants is obligated to engage in creation and/or redemption transactions. The Fund has a limited number of institutions that may act as Authorized Participants on an agency basis (i.e., on behalf of other market participants). In addition, to the extent that securities held by the Fund are traded outside a collateralized settlement system, Authorized Participants may be required to post collateral on certain trades on an agency basis (on behalf of other market participants), which only a limited number of Authorized Participants may be able to do. To the extent that Authorized Participants exit the business or are unable to proceed with creation or redemption orders with respect to the ETF Class shares of the Fund and no other Authorized Participant is able to step forward to create or redeem creation units (“Creation Units”), the Fund’s ETF Class shares may be more likely to trade at a premium or discount to NAV and possibly face trading halts or delisting.</td> </tr></table> <p id="xdx_A85_eoef--RiskTextBlock_hoef--RiskAxis__custom--ForeignInvestmentRiskMember_zvjQve209Ql2" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; margin-left: 0; text-align: justify">Foreign Investment Risk - Investments in securities of foreign issuers may involve risks including adverse fluctuations in currency exchange rates, political instability, confiscations, taxes or restrictions on currency exchange, difficulty in selling foreign investments, and reduced legal protection. These risks may be more pronounced for investments in countries that are less diversified and where communications, transportation and economic infrastructures are less developed. Such countries ordinarily have less established legal, political, business and social frameworks. At times the prices of equity securities of foreign issuers may be extremely volatile. <p id="xdx_A83_eoef--RiskTextBlock_hoef--RiskAxis__custom--GrowthCompanyRiskMember_z4CDC9iLH7hd" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; margin-left: 0; text-align: justify">Growth Company Risk - Growth company stocks may trade at higher multiples of current earnings than other equity securities and, therefore, may be more sensitive to changes in current or expected earnings than other equity securities and may be more volatile. If growth companies do not increase their earnings at a rate expected by investors, the market price of the stock may decline significantly, even if earnings show an absolute increase. Growth company stocks also typically lack the dividend yield that can cushion stock prices in market downturns. These risks may be more pronounced in companies that are in the earlier stages of their growth cycle. <p id="xdx_A85_eoef--RiskTextBlock_hoef--RiskAxis__custom--LiquidityRiskMember_zjfKEA3HrFH" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; margin-left: 0; text-align: justify">Liquidity Risk - Due to a lack of demand in the marketplace or other factors, the Fund may not be able to sell some or all of its investments promptly, or may only be able to sell investments at less than desired prices. <p id="xdx_A8C_eoef--RiskTextBlock_hoef--RiskAxis__custom--ManagementRiskMember_zPyd38uDSvO7" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; margin-left: 0; text-align: justify">Management Risk - The Fund is an actively managed portfolio, and the value of the Fund may be reduced if Thornburg pursues unsuccessful investments or fails to correctly identify risks affecting the broad economy or specific issuers in which the Fund invests. <p id="xdx_A8D_eoef--RiskTextBlock_hoef--RiskAxis__custom--MarketAndEconomicRiskMember_z80OAnLWBHJj" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; margin-left: 0; text-align: justify">Market and Economic Risk - The value of the Fund’s investments may decline and its share value may be reduced due to changes in general economic and market conditions. The value of a security may change in response to developments affecting entire economies, markets or industries, including changes in interest rates, political and legal developments, and general market volatility. <p id="xdx_A86_eoef--RiskTextBlock_hoef--RiskAxis__custom--RisksAffectingSpecificIssuersMember_zhXmmshKqIr9" style="font: 10pt Times New Roman, Times, Serif; margin-top: 0pt; margin-bottom: 0pt; margin-left: 0; text-align: justify">Risks Affecting Specific Issuers - The value of a security may decline in response to developments affecting the specific issuer of the security, even if the overall industry or economy is unaffected. These developments may include a variety of factors, including but not limited to management issues or other corporate disruption, a decline in revenues or profitability, an increase in costs, or an adverse effect on the issuer’s competitive position. Past Performance of the Fund The following information provides some indication of the risks of investing in the Focus Growth Fund by showing how the investment results of the Fund’s Class I shares varied from year to year. Because the Fund’s ETF Class shares had not commenced operations as of the date of this Prospectus, the bar chart shows how the annual total returns for Class I shares have been different in each full year shown. Class I shares are a mutual fund class of shares of the Fund and are not offered in this Prospectus. Class I shares would have substantially similar annual returns to ETF Class shares because the shares are invested in the same portfolio of securities and the annual returns at NAV (assuming ETF Class shares are bought and sold without any premium or discount) would differ only to the extent that Class I shares do not have the same expenses as the ETF Class shares (ETF Class shares have lower total expenses than Class I shares). Performance information for ETF Class shares will be provided after such shares have one full calendar year of performance. The average annual total return figures compare Class I share performance to the Russell 1000 Index-Total Return, a broad-based securities market index that represents the overall applicable market in which the Fund invests, and the Russell 1000 Growth Index-Total Return, an additional index that represents the market sectors which Thornburg believes are more representative of the Fund’s investment universe. These indexes are not actively managed and are not available for direct investment. As of March 23, 2026, the Fund no longer compares its returns to the Russell 3000 Index—Total Return or Russell 2500 Growth Index—Total Return because the current indices better reflect the Fund’s current investment universe (as described below). The performance information shown below is as of the calendar year ended December 31, 2025. Before March 23, 2026, the Fund was managed with a different principal investment strategy under the name “Thornburg Small/Mid Cap Growth Fund” and may have achieved different performance results under its current principal investment strategy from the performance shown for periods before that date. Past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. The bar charts and performance tables assume reinvestment of dividends and distributions. Updated performance information may be obtained on the Thornburg website at Thornburg.com or by calling 1-800-847-0200. The following information provides some indication of the risks of investing in the Focus Growth Fund by showing how the investment results of the Fund’s Class I shares varied from year to year. Past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. Thornburg.com 1-800-847-0200 Annual Total Returns - Class I Shares <div id="xdx_A8A_eoef--BarChartTableTextBlock_zKlS0Zt22YWa"></div> <table cellpadding="0" cellspacing="0" id="xdx_A55_zvDNHrKzH3H2" style="font: 10pt Times New Roman, Times, Serif; display: none; visibility: hidden; border-collapse: collapse; width: 100%" summary="xdx: Disclosure - Annual Total Returns"> <tr style="vertical-align: top; text-align: left"> <td style="width: 50%"> </td> <td id="xdx_48D_eoef--AnnlRtrPct_dp_hoef--ClassAxis__custom--C000032377Member_zuNjwLUEf839" style="width: 50%"></td></tr> <tr id="xdx_415_20160101__20161231_zwEZvVCadtOa" style="vertical-align: top; text-align: left"> <td>2016</td> <td>-1.95%</td></tr> <tr id="xdx_415_20170101__20171231_zwWupiS6ZRj3" style="vertical-align: top; text-align: left"> <td>2017</td> <td>24.40%</td></tr> <tr id="xdx_41C_20180101__20181231_zqDd0kjIDgzg" style="vertical-align: top; text-align: left"> <td>2018</td> <td>-2.20%</td></tr> <tr id="xdx_419_20190101__20191231_z75fQgb9cO27" style="vertical-align: top; text-align: left"> <td>2019</td> <td>29.37%</td></tr> <tr id="xdx_41A_20200101__20201231_zPBYCHKZCgm2" style="vertical-align: top; text-align: left"> <td>2020</td> <td>42.08%</td></tr> <tr id="xdx_416_20210101__20211231_z88aUybJXF47" style="vertical-align: top; text-align: left"> <td>2021</td> <td>-3.99%</td></tr> <tr id="xdx_418_20220101__20221231_ziKhRrddHxM5" style="vertical-align: top; text-align: left"> <td>2022</td> <td>-33.87%</td></tr> <tr id="xdx_418_20230101__20231231_zxbVtjoG0Vib" style="vertical-align: top; text-align: left"> <td>2023</td> <td>20.15%</td></tr> <tr id="xdx_417_20240101__20241231_zvAzVtkjERw4" style="vertical-align: top; text-align: left"> <td>2024</td> <td>20.20%</td></tr> <tr id="xdx_416_20250101__20251231_zHYTDksrAo9l" style="vertical-align: top; text-align: left"> <td>2025</td> <td>4.82%</td></tr> </table> <img alt="" src="thornburgchart003.jpg" style="height: 299px; width: 500px"/> -0.0195 0.2440 -0.0220 0.2937 0.4208 -0.0399 -0.3387 0.2015 0.2020 0.0482 <div id="xdx_A8D_eoef--BarChartClosingTextBlock_zbgTyFySz8E"></div> <table cellpadding="0" cellspacing="0" style="font: 10pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse"> <tr style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom"> <td style="font: 10pt Times New Roman, Times, Serif; padding-right: 5.4pt; padding-left: 5.4pt"> </td> <td style="font: 10pt Times New Roman, Times, Serif; background-color: #234B8D; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">Total Returns</td> <td style="font: 10pt Times New Roman, Times, Serif; background-color: #234B8D; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">Quarter ended</td></tr> <tr style="font: 10pt Times New Roman, Times, Serif; background-color: #E9EDF3"> <td style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom; padding-right: 5.4pt; padding-left: 5.4pt">Highest Quarterly Results</td> <td style="font: 10pt Times New Roman, Times, Serif; vertical-align: top; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">31.07%</td> <td style="font: 10pt Times New Roman, Times, Serif; vertical-align: top; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">6/30/2020</td></tr> <tr style="font: 10pt Times New Roman, Times, Serif"> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; vertical-align: bottom; padding-right: 5.4pt; padding-left: 5.4pt">Lowest Quarterly Results</td> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; vertical-align: top; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">-24.80%</td> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; vertical-align: top; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">6/30/2022</td></tr> </table> Highest Quarterly Results 0.3107 2020-06-30 Lowest Quarterly Results -0.2480 2022-06-30 Average Annual Total Returns (periods ended 12-31-25) <div id="xdx_A88_eoef--PerformanceTableTextBlock_zWPmlETA1ff2"></div> <table cellpadding="0" cellspacing="0" id="xdx_A53_dU_zE7Xkr8mE9H6" style="font: 10pt Times New Roman, Times, Serif; width: 100%; border-collapse: collapse" summary="xdx: Disclosure - Average Annual Total Returns"> <tr style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom"> <td style="font: 10pt Times New Roman, Times, Serif; padding-right: 5.4pt; padding-left: 5.4pt">CLASS I SHARES</td> <td id="xdx_495_20250101__20251231_zx68OZmoYxDe" style="font: 10pt Times New Roman, Times, Serif; background-color: #234B8D; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">1 YEAR</td> <td id="xdx_491_20210101__20251231_zojshZ9iSCB2" style="font: 10pt Times New Roman, Times, Serif; background-color: #234B8D; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">5 YEARS</td> <td id="xdx_491_20160101__20251231_zhK0V5Uc69Ya" style="font: 10pt Times New Roman, Times, Serif; background-color: #234B8D; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">10 YEARS</td></tr> <tr id="xdx_402_eoef--AvgAnnlRtrPct_dp_hoef--ClassAxis__custom--C000032377Member_z1T7WAu9iExe" style="font: 10pt Times New Roman, Times, Serif; background-color: #E9EDF3"> <td style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom; padding-right: 5.4pt; padding-left: 5.4pt">Return Before Taxes</td> <td style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">4.82%</td> <td style="font: 10pt Times New Roman, Times, Serif; vertical-align: top; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">-0.79%</td> <td style="font: 10pt Times New Roman, Times, Serif; vertical-align: top; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">7.74%</td></tr> <tr id="xdx_40D_eoef--AvgAnnlRtrPct_dp_hoef--ClassAxis__custom--C000032377Member__oef--PerformanceMeasureAxis__oef--AfterTaxesOnDistributionsMember_zVMsJDp1W7M8" style="font: 10pt Times New Roman, Times, Serif"> <td style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom; padding-right: 5.4pt; padding-left: 5.4pt">Return After Taxes on Distributions</td> <td style="font: 10pt Times New Roman, Times, Serif; vertical-align: top; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">4.82%</td> <td style="font: 10pt Times New Roman, Times, Serif; vertical-align: top; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">-2.30%</td> <td style="font: 10pt Times New Roman, Times, Serif; vertical-align: top; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">6.54%</td></tr> <tr id="xdx_401_eoef--AvgAnnlRtrPct_dp_hoef--ClassAxis__custom--C000032377Member__oef--PerformanceMeasureAxis__oef--AfterTaxesOnDistributionsAndSalesMember_zIvSnENfupu6" style="font: 10pt Times New Roman, Times, Serif; background-color: #E9EDF3"> <td style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom; padding-right: 5.4pt; padding-left: 5.4pt">Return After Taxes on Distributions and Sale of Fund Shares</td> <td style="font: 10pt Times New Roman, Times, Serif; vertical-align: top; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">2.85%</td> <td style="font: 10pt Times New Roman, Times, Serif; vertical-align: top; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">-0.54%</td> <td style="font: 10pt Times New Roman, Times, Serif; vertical-align: top; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">6.27%</td></tr> <tr id="xdx_40C_eoef--AvgAnnlRtrPct_dp_hoef--PerformanceMeasureAxis__custom--Russell1000IndexTotalReturnMember_zpIm6u53S0rh" style="font: 10pt Times New Roman, Times, Serif"> <td style="font: 10pt Times New Roman, Times, Serif; vertical-align: bottom; padding-right: 5.4pt; padding-left: 5.4pt">Russell 1000 Index-Total Return (reflects no deduction for fees, expenses, or taxes)</td> <td style="font: 10pt Times New Roman, Times, Serif; vertical-align: top; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">17.37%</td> <td style="font: 10pt Times New Roman, Times, Serif; vertical-align: top; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">13.59%</td> <td style="font: 10pt Times New Roman, Times, Serif; vertical-align: top; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">14.59%</td></tr> <tr id="xdx_40E_eoef--AvgAnnlRtrPct_dp_hoef--PerformanceMeasureAxis__custom--Russell1000GrowthIndexTotalReturnMember_zFBqRPqoGwWl" style="font: 10pt Times New Roman, Times, Serif; background-color: #E9EDF3"> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; vertical-align: bottom; padding-right: 5.4pt; padding-left: 5.4pt">Russell 1000 Growth Index-Total Return (reflects no deduction for fees, expenses, or taxes)</td> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; vertical-align: top; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">18.56%</td> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; vertical-align: top; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">15.32%</td> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; vertical-align: top; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">18.13%</td></tr> <tr id="xdx_409_eoef--AvgAnnlRtrPct_dp_hoef--PerformanceMeasureAxis__custom--Russell3000IndexTotalReturnMember_zpUHOTfTGdI9" style="font: 10pt Times New Roman, Times, Serif"> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; vertical-align: bottom; padding-right: 5.4pt; padding-left: 5.4pt">Russell 3000 Index-Total Return (reflects no deduction for fees, expenses, or taxes)</td> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; vertical-align: top; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">17.15%</td> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; vertical-align: top; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">13.15%</td> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; vertical-align: top; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">14.29%</td></tr> <tr id="xdx_400_eoef--AvgAnnlRtrPct_dp_hoef--PerformanceMeasureAxis__custom--Russell2500GrowthIndexTotalReturnMember_zzoZCSZRLC3i" style="font: 10pt Times New Roman, Times, Serif; background-color: #E9EDF3"> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; vertical-align: bottom; padding-right: 5.4pt; padding-left: 5.4pt">Russell 2500 Growth Index-Total Return (reflects no deduction for fees, expenses, or taxes)</td> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; vertical-align: top; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">10.31%</td> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; vertical-align: top; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">2.98%</td> <td style="border-bottom: #234B8D 1pt solid; font: 10pt Times New Roman, Times, Serif; vertical-align: top; text-align: center; padding-right: 5.4pt; padding-left: 5.4pt">10.55%</td></tr> </table> 0.0482 -0.0079 0.0774 0.0482 -0.0230 0.0654 0.0285 -0.0054 0.0627 (reflects no deduction for fees, expenses, or taxes) 0.1737 0.1359 0.1459 (reflects no deduction for fees, expenses, or taxes) 0.1856 0.1532 0.1813 (reflects no deduction for fees, expenses, or taxes) 0.1715 0.1315 0.1429 (reflects no deduction for fees, expenses, or taxes) 0.1031 0.0298 0.1055 After-tax returns are calculated using the highest historical individual federal marginal income tax rates, and do not reflect state or local income taxes. Actual after-tax returns depend on an investor’s own tax situation and may differ from the returns shown, and after-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. The after-tax returns shown relate only to Class I shares, and after-tax returns for other share classes will vary. After-tax returns are calculated using the highest historical individual federal marginal income tax rates, and do not reflect state or local income taxes. Actual after-tax returns depend on an investor’s own tax situation and may differ from the returns shown, and after-tax returns shown are not relevant to investors who hold their Fund shares through tax-deferred arrangements, such as 401(k) plans or individual retirement accounts. The after-tax returns shown relate only to Class I shares, and after-tax returns for other share classes will vary. Management fees have been restated to reflect contractual changes to the management fees paid by the Fund. ETF Class shares of the Fund are new, so “Other Expenses" shown are based on anticipated fees and expenses for the first full fiscal year. Thornburg Investment Management, Inc. (“Thornburg”) has contractually agreed to waive fees and reimburse expenses incurred by the Fund so that actual ETF Class expenses (excluding taxes, interest expenses, acquired fund fees and expenses, brokerage commissions, borrowing costs, expenses relating to short sales, and unusual expenses such as contingency fees or litigation costs) do not exceed 0.79%. The agreement to waive fees and reimburse expenses may be terminated by the Fund’s Trustees at any time, but may not be terminated by Thornburg before March 27, 2027, unless Thornburg ceases to be the investment advisor of the Fund prior to that date. Thornburg may recoup amounts waived or reimbursed during the Fund’s fiscal year if actual expenses fall below the expense cap during that same fiscal year. Management fees have been restated to reflect contractual changes to the management fees paid by the Fund. ETF Class shares of the Fund are new, so “Other Expenses" shown are based on anticipated fees and expenses for the first full fiscal year. Thornburg Investment Management, Inc. (“Thornburg”) has contractually agreed to waive fees and reimburse expenses incurred by the Fund so that actual ETF Class expenses (excluding taxes, interest expenses, acquired fund fees and expenses, brokerage commissions, borrowing costs, expenses relating to short sales, and unusual expenses such as contingency fees or litigation costs) do not exceed 0.79%. The agreement to waive fees and reimburse expenses may be terminated by the Fund’s Trustees at any time, but may not be terminated by Thornburg before March 27, 2027, unless Thornburg ceases to be the investment advisor of the Fund prior to that date. Thornburg may recoup amounts waived or reimbursed during the Fund’s fiscal year if actual expenses fall below the expense cap during that same fiscal year.