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THORNBURG INVESTMENT TRUST

Funds Prospectus

FEBRUARY 1, 2023

Thornburg Global Opportunities Fund

(“Global Opportunities Fund”)

Class A: THOAX

Class C: THOCX

Class I: THOIX

Thornburg International Equity Fund

(“International Equity Fund”)

Class A: TGVAX

Class C: THGCX

Class I: TGVIX

Thornburg Better World
International Fund

(“Better World International Fund”)

Class A: TBWAX

Class C: TBWCX

Class I: TBWIX

Thornburg International Growth Fund

(“International Growth Fund”)

Class A: TIGAX

Class C: TIGCX

Class I: TINGX

Thornburg Developing World Fund

(“Developing World Fund”)

Class A: THDAX

Class C: THDCX

Class I: THDIX

Thornburg Small/Mid Cap Core Fund

(“Small/Mid Cap Core Fund”)

Class A: TVAFX

Class C: TVCFX

Class I: TVIFX

Thornburg Small/Mid Cap
Growth Fund

(“Small/Mid Cap Growth Fund”)

Class A: THCGX

Class C: TCGCX

Class I: THIGX

Thornburg Investment Income Builder Fund

(“Income Builder Fund”)

Class A: TIBAX

Class C: TIBCX

Class I: TIBIX

Thornburg Summit Fund

(“Summit Fund”)

Class A: TSAMX

Class I: TSUMX

Thornburg Limited Term U.S. Government Fund

(“Limited Term U.S. Government Fund”)

Class A: LTUSX

Class C: LTUCX

Class C2: LTUQX

Class I: LTUIX

Thornburg Limited Term Income Fund

(“Limited Term Income Fund”)

Class A: THIFX

Class C: THICX

Class C2: THIQX

Class I: THIIX

Thornburg Ultra Short Income Fund

(“Ultra Short Income Fund”)

Class A: TLDAX

Class I: TLDIX

Thornburg Strategic Income Fund

(“Strategic Income Fund”)

Class A: TSIAX

Class C: TSICX

Class I: TSIIX

Thornburg Short Duration
Municipal Fund

(“Short Duration Municipal Fund”)

Class A: TLMAX

Class I: TLMIX

Thornburg Limited Term
Municipal Fund

(“Limited Term Municipal Fund”)

Class A: LTMFX

Class C: LTMCX

Class C2: LTMQX

Class I: LTMIX

Thornburg California Limited Term Municipal Fund

(“Limited Term California Fund”)

Class A: LTCAX

Class C: LTCCX

Class C2: LTCQX

Class I: LTCIX

Thornburg New Mexico Intermediate Municipal Fund

(“Intermediate New Mexico Fund”)

Class A: THNMX

Class D: THNDX

Class I: THNIX

Thornburg New York Intermediate Municipal Fund

(“Intermediate New York Fund”)

Class A: THNYX

Class I: TNYIX

Thornburg Intermediate
Municipal Fund

(“Intermediate Municipal Fund”)

Class A: THIMX

Class C: THMCX

Class C2: THMQX

Class I: THMIX

Thornburg Strategic
Municipal Income Fund

(“Strategic Municipal Income Fund”)

Class A: TSSAX

Class C: TSSCX

Class I: TSSIX

These securities have not been approved or disapproved by the Securities and Exchange Commission nor has the Securities and Exchange Commission passed upon the accuracy or adequacy of this Prospectus. Any representation to the contrary is a criminal offense.

THORNBURG INVESTMENT TRUSTPROSPECTUSFEBRUARY 1, 2023

i

Thornburg investment trust

Table of Contents

1

PROSPECTUSFEBRUARY 1, 2023THORNBURG INVESTMENT TRUST

Fund Summary

Global Opportunities Fund

Investment Goal

The Fund seeks long-term capital appreciation by investing in equity and debt securities of all types from issuers around the world.

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for discounts from the sales charges applicable to Class A shares if you or other qualifying account holders invest, or agree to invest in the future, at least $50,000 in the Thornburg Funds. More information about this and other discounts and sales charge waivers is available from your financial intermediary, in the Prospectus under the captions “Class A Sales Charge Waivers,” beginning on page 147, and “Appendix A – Sales Charge Waivers Offered by Financial Intermediaries,” beginning on page 200, and in the Statement of Additional Information under the caption “Additional Information Respecting Purchase and Redemption of Shares,” beginning on page 92.

Shareholder Fees

(fees paid directly from your investment)

 

Class A

Class C

Class I

       

Maximum Sales Charge (Load) Imposed on Purchases
(as a percentage of offering price)

4.50%

none

none

Maximum Deferred Sales Charge (Load)
(as a percentage of redemption proceeds or original purchase price,
whichever is lower)

none(1)

1.00%(2)

none

Annual Fund Operating Expenses

(expenses that you pay each year as a percentage of the value of your investment)

 

Class A

Class C

Class I

Management Fees

0.85%

0.85%

0.85%

Distribution and Service (12b-1) Fees

0.25%

1.00%

none

Other Expenses

0.25%

0.26%

0.21%

Total Annual Fund Operating Expenses

1.35%

2.11%

1.06%

Fee Waiver/Expense Reimbursement

  

  

(0.07)%(3)

Total Annual Fund Operating Expenses After
Fee Waiver/Expense Reimbursement

1.35%

2.11%

0.99%

(1) Up to a 1.00% contingent deferred sales charge (CDSC) is imposed on redemptions of any part or all of a purchase of $1 million or more within 12 months of purchase.
(2) Imposed only on redemptions of Class C shares within 12 months of purchase.
(3) Thornburg Investment Management, Inc. (“Thornburg”) has contractually agreed to waive fees and reimburse expenses incurred by the Fund so that actual Class I expenses (excluding taxes, interest expenses, 12b-1 distribution and service fees, 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 0.99%. 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 February 1, 2024, 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.

THORNBURG INVESTMENT TRUSTPROSPECTUSFEBRUARY 1, 2023

2

Fund Summary Global Opportunities Fund

Example.

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.

The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem 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 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:

 

1 Year

3 Years

5 Years

10 Years

Class A Shares

$581

$858

$1,156

$2,001

Class C Shares

$314

$661

$1,134

$2,441

Class I Shares

$101

$330

$578

$1,288

You would pay the following expenses if you did not redeem your Class C shares:

 

1 Year

3 Years

5 Years

10 Years

Class C Shares

$214

$661

$1,134

$2,441

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 26.92% of the average value of its portfolio.

Principal Investment Strategies

The Fund pursues its investment goal by investing primarily in a broad range of equity securities, including common stocks, preferred stocks and publicly traded real estate investment trusts. The Fund may invest in any stock or other equity security which its investment advisor, Thornburg Investment Management, Inc. (“Thornburg”), believes may assist the Fund in pursuing its goal, including smaller companies with market capitalizations less than $500 million.

The Fund portfolio includes investments in both domestic securities and securities of issuers domiciled in or economically tied to countries outside the United States, including developing countries. Relative proportions of each will vary from time to time, depending upon the advisor’s view of specific investment opportunities and macro-economic factors. Under normal market conditions, the Fund invests a significant portion of its assets in issuers domiciled in or economically tied to countries outside the United States.

The Fund’s investments are determined by individual issuer and industry analysis. Investment decisions are based on domestic and international economic developments, outlooks for securities markets, interest rates and inflation, the supply and demand for securities, and analysis of specific issuers.

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.

 

3

PROSPECTUSFEBRUARY 1, 2023THORNBURG INVESTMENT TRUST

Fund Summary Global Opportunities Fund

Principal Investment Risks

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. The value of the Fund’s shares varies from day to day and over time, and when you sell your shares they may be worth less than what you paid for them. The following is a summary of the principal risks of investing in the Fund. The risks are presented in alphabetical order to facilitate readability, and their order does not imply that the realization of one risk is more likely to occur or have a greater adverse impact than another risk. The relative significance of each risk below may change over time.

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.

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.

Developing Country Risk – The risks which may affect investments in foreign issuers (see “Foreign Investment Risk,” below) may be more pronounced for investments in developing countries because the economies of those countries are usually less diversified, communications, transportation and economic infrastructures are less developed, and developing countries ordinarily have less established legal, political, business and social frameworks. At times the prices of equity securities of a developing country issuer may be extremely volatile. An issuer domiciled in a developed country may be similarly affected by these developing country risks to the extent that the issuer conducts its business in developing countries.

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.

Foreign Currency Risk – Fluctuations in currency exchange rates can adversely affect the value of the Fund’s foreign investments. Such fluctuations may occur for a number of reasons, including market and economic conditions, or a government’s decision to devalue its currency or impose currency controls.

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.

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. This risk may be more pronounced for the Fund’s investments in developing countries.

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.

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.

Real Estate Risk – The Fund’s investments in publicly traded real estate investment trusts (“REITs”) are subject to risks affecting real estate investments generally (including market conditions, competition, property obsolescence, changes in interest rates and casualty to real estate), as well as risks specifically affecting REITs (the quality and skill of REIT management and the internal expenses of the REIT).

Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity.

 

THORNBURG INVESTMENT TRUSTPROSPECTUSFEBRUARY 1, 2023

4

Fund Summary Global Opportunities Fund

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.

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.

Small and Mid-Cap Company Risk – Investments in small-capitalization companies and mid-capitalization companies may involve additional risks, which may be relatively higher with smaller companies. These additional risks may result from limited product lines, more limited access to markets and financial resources, greater vulnerability to competition and changes in markets, lack of management depth, increased volatility in share price, and possible difficulties in valuing or selling these investments.

Additional information about Fund investments, investment strategies and risks of investing in the Fund appears beginning on page 118 of the Prospectus.

Past Performance of the Fund

The following information provides some indication of the risks of investing in Global Opportunities Fund by showing how the Fund’s investment results vary from year to year. The bar chart shows how the annual total returns for Class A shares have been different in each full year shown. The average annual total return figures compare Class A, Class C and Class I share performance to the MSCI All Country World Net Total Return USD Index, which represents a broad measure of both domestic and foreign equity market performance. Past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. The performance information shown is as of the calendar year ended December 31, 2022. Updated performance information may be obtained on the Thornburg website at Thornburg.com or by calling 1-800-847-0200.

 

Annual Total Returns – Class A Shares

 
2013 28.18%
2014 18.44%
2015 1.12%
2016 3.64%
2017 21.64%
2018 -20.92%
2019 28.35%
2020 22.32%
2021 14.42%
2022 -10.35%

5

PROSPECTUSFEBRUARY 1, 2023THORNBURG INVESTMENT TRUST

Fund Summary Global Opportunities Fund

 

 

Total
Returns

Quarter
ended

Highest Quarterly Results

21.72

6/30/2020

Lowest Quarterly Results

-24.82

3/31/2020

The sales charge for Class A shares is not reflected in the returns shown on the bar chart, and the returns would be less if the charge was taken into account.

 

Average Annual Total Returns

(periods ended 12-31-22)

Class A Shares

1 Year

5 Years

10 Years

Return Before Taxes

-14.39

4.00

8.94

Return After Taxes on Distributions

-15.29

2.43

8.03

Return After Taxes on Distributions and Sale of Fund Shares

-8.16

2.83

7.13

MSCI All Country World Net Total Return USD Index
(reflects no deduction for fees, expenses, or U.S. taxes)

-18.36

5.23

7.98

Class C Shares

1 Year

5 Years

10 Years

Return Before Taxes

-11.88

4.18

8.62

MSCI All Country World Net Total Return USD Index
(reflects no deduction for fees, expenses, or U.S. taxes)

-18.36

5.23

7.98

Class I Shares

1 Year

5 Years

10 Years

Return Before Taxes

-10.08

5.27

9.81

MSCI All Country World Net Total Return USD Index
(reflects no deduction for fees, expenses, or U.S. taxes)

-18.36

5.23

7.98

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 A shares, and after-tax returns for other share classes will vary.

Management

Investment Advisor: Thornburg Investment Management, Inc.

Portfolio Managers:

Brian J. McMahon, the vice chairman of the Trust and a managing director and chief investment strategist of Thornburg, has been one of the persons jointly and primarily responsible for management of the Fund since its inception.

Miguel Oleaga, a managing director of Thornburg, has been one of the persons jointly and primarily responsible for management of the Fund since 2020.

THORNBURG INVESTMENT TRUSTPROSPECTUSFEBRUARY 1, 2023

6

Fund Summary Global Opportunities Fund

Purchase and Sale of Fund Shares

The minimum amounts for an initial investment in Fund shares and for subsequent investments in Fund shares are shown below. If you purchase your shares through a financial intermediary, the intermediary may impose its own minimum investment requirements. The minimums shown below may also be reduced or waived by the Funds under certain circumstances.

Minimum Initial Investment

Class A

Class C

Class I

Investors Purchasing through a Fee-Based Account with a Financial Intermediary

$2,500

   N/A

    $2,500

Individual Retirement Accounts

$2,000

$2,000

      N/A

All Others

$5,000

$5,000

$2,500,000

Minimum Subsequent Investments (all accounts)

Class A

Class C

Class I

 

  $100

  $100

     $100

The Fund’s shares are redeemable on any business day. If you hold your Fund shares through a financial intermediary, you should contact your intermediary to redeem shares. If you hold your shares directly with the Funds, you may redeem shares at any time by mail (c/o the Fund’s Transfer Agent, SS&C GIDS, Inc., at P.O. Box 219017, Kansas City, Missouri 64121-9017) or by telephone (1-800-847-0200).

Tax Information

Distributions to shareholders will generally be taxable to shareholders as ordinary income or capital gains for federal income tax purposes. Distributions may also be subject to state and local taxes. See “Taxes” on page 158 of the Prospectus.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase shares of a Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund, its investment advisor and/or its distributor may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.

7

PROSPECTUSFEBRUARY 1, 2023THORNBURG INVESTMENT TRUST

Fund Summary

International Equity Fund

Investment Goal

The Fund seeks long-term capital appreciation by investing in equity and debt securities of all types.

The secondary, non-fundamental goal of the Fund is to seek some current income.

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for discounts from the sales charges applicable to Class A shares if you or other qualifying account holders invest, or agree to invest in the future, at least $50,000 in the Thornburg Funds. More information about this and other discounts and sales charge waivers is available from your financial intermediary, in the Prospectus under the captions “Class A Sales Charge Waivers,” beginning on page 147, and “Appendix A – Sales Charge Waivers Offered by Financial Intermediaries,” beginning on page 200, and in the Statement of Additional Information under the caption “Additional Information Respecting Purchase and Redemption of Shares,” beginning on page 92.

Shareholder Fees

(fees paid directly from your investment)

 

Class A

Class C

Class I

Maximum Sales Charge (Load) Imposed on Purchases
(as a percentage of offering price)

4.50%

none

none

Maximum Deferred Sales Charge (Load)
(as a percentage of redemption proceeds or original purchase price,
whichever is lower)

none(1)

1.00%(2)

none

Annual Fund Operating Expenses

(expenses that you pay each year as a percentage of the value of your investment)

 

Class A

Class C

Class I

Management Fees

0.76%

0.76%

0.76%

Distribution and Service (12b-1) Fees

0.25%

1.00%

none

Other Expenses

0.37%

0.29%

0.24%

Total Annual Fund Operating Expenses

1.38%

2.05%

1.00%

Fee Waiver/Expense Reimbursement

  

  

(0.10)%(3)

Total Annual Fund Operating Expenses After
Fee Waiver/Expense Reimbursement

1.38%

2.05%

0.90%

(1) Up to a 1.00% contingent deferred sales charge (CDSC) is imposed on redemptions of any part or all of a purchase of $1 million or more within 12 months of purchase.
(2) Imposed only on redemptions of Class C shares within 12 months of purchase.
(3) Thornburg Investment Management, Inc. (“Thornburg”) has contractually agreed to waive fees and reimburse expenses incurred by the Fund so that actual Class I expenses (excluding taxes, interest expenses, 12b-1 distribution and service fees, 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 0.90%. 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 February 1, 2024, 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.

THORNBURG INVESTMENT TRUSTPROSPECTUSFEBRUARY 1, 2023

8

Fund Summary International Equity Fund

Example.

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.

The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem 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 remain the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

 

1 Year

3 Years

5 Years

10 Years

Class A Shares

$584

$867

$1,171

$2,033

Class C Shares

$308

$643

$1,103

$2,379

Class I Shares

$92

$308

$543

$1,216

You would pay the following expenses if you did not redeem your Class C shares:

 

1 Year

3 Years

5 Years

10 Years

Class C Shares

$208

$643

$1,103

$2,379

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 48.88% of the average value of its portfolio.

Principal Investment Strategies

The Fund invests primarily in common stocks of non-U.S. companies and in depositary receipts associated with such stocks. The Fund may invest in developing countries, but under normal conditions those investments are expected to comprise a smaller proportion of the Fund than investments in developed countries. Under normal conditions, the Fund will invest at least 80% of its net assets in common stocks or depositary receipts.

The Fund’s investment advisor, Thornburg Investment Management, Inc. (“Thornburg”), intends to invest on an opportunistic basis where the Fund’s portfolio managers believe 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, and emerging franchises, when the portfolio managers believe these issues are value priced. 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 that reflect unfavorable market perceptions of the company or industry fundamentals. The Fund may invest in companies of any size, but invests primarily in the large and middle capitalization range of publicly traded companies.

Thornburg primarily uses individual issuer and industry analysis to make investment decisions. Value, for purposes of the Fund’s selection criteria, may consider both current and projected measures. Among the specific factors considered by Thornburg in identifying securities for inclusion in the Fund are:

profitability

price/earnings ratio

price/book value ratio

price/cash flow ratio

debt/capital ratio

dividend characteristics

security and consistency of revenues

EV (enterprise value)/EBITDA (earnings before interest, taxes, depreciation and amortization) ratio

undervalued assets

earnings growth potential

industry growth characteristics

industry leadership

 

9

PROSPECTUSFEBRUARY 1, 2023THORNBURG INVESTMENT TRUST

Fund Summary International Equity Fund

franchise value

potential for favorable developments

EBIT (earnings before interest and taxes)/interest expense ratio

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 the advisor 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 the advisor 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.

The Fund’s policy of investing at least 80% of its net assets in common stocks or depositary receipts may be changed by the Fund’s Trustees without a shareholder vote upon 60 days’ notice to shareholders.

Principal Investment Risks

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. The value of the Fund’s shares varies from day to day and over time, and when you sell your shares they may be worth less than what you paid for them. The following is a summary of the principal risks of investing in the Fund. The risks are presented in alphabetical order to facilitate readability, and their order does not imply that the realization of one risk is more likely to occur or have a greater adverse impact than another risk. The relative significance of each risk below may change over time.

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.

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.

Developing Country Risk – The risks which may affect investments in foreign issuers (see “Foreign Investment Risk,” below) may be more pronounced for investments in developing countries because the economies of those countries are usually less diversified, communications, transportation and economic infrastructures are less developed, and developing countries ordinarily have less established legal, political, business and social frameworks. At times the prices of equity securities of a developing country issuer may be extremely volatile. An issuer domiciled in a developed country may be similarly affected by these developing country risks to the extent that the issuer conducts its business in developing countries.

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.

Foreign Currency Risk – Fluctuations in currency exchange rates can adversely affect the value of the Fund’s foreign investments. Such fluctuations may occur for a number of reasons, including market and economic conditions, or a government’s decision to devalue its currency or impose currency controls.

 

THORNBURG INVESTMENT TRUSTPROSPECTUSFEBRUARY 1, 2023

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Fund Summary International Equity Fund

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.

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.

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.

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.

Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity.

Risks Affecting Investments in China – A significant portion of the Fund’s assets may be invested in companies exposed to China. Risks affecting investments in China include a potential downturn in the Chinese economy, reduced liquidity or increased price volatility in the Chinese securities markets as a result of trading suspensions affecting Chinese issuers or other factors, the potential that the Chinese government may expand restrictions on foreign investments or the repatriation of capital, and the implementation of new tariffs or other trade barriers by China or its trading partners. A lack of transparency respecting Chinese companies may also reduce the Fund’s ability to conduct diligence respecting those companies’ accounting and governance standards, which may in turn reduce the Fund’s ability to detect fraudulent practices that may adversely affect the companies’ stock prices.

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.

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.

Small and Mid-Cap Company Risk – Investments in small-capitalization companies and mid-capitalization companies may involve additional risks, which may be relatively higher with smaller companies. These additional risks may result from limited product lines, more limited access to markets and financial resources, greater vulnerability to competition and changes in markets, lack of management depth, increased volatility in share price, and possible difficulties in valuing or selling these investments.

Additional information about Fund investments, investment strategies, and risks of investing in the Fund appears below beginning on page 118 of the Prospectus.

Past Performance of the Fund

The following information provides some indication of the risks of investing in International Equity Fund by showing how the Fund’s investment results vary from year to year. The bar chart shows how the annual total returns for Class A shares have been different in each full year shown. The average annual total return figures compare Class A, Class C and Class I share performance to the MSCI All Country World ex USA Net Total Return USD Index (primary index) and the MSCI EAFE (Europe, Australasia, Far East) Net Total Return USD Index (secondary index), each of which is a broad measure of market performance. Past performance (before

11

PROSPECTUSFEBRUARY 1, 2023THORNBURG INVESTMENT TRUST

Fund Summary International Equity Fund

and after taxes) is not necessarily an indication of how the Fund will perform in the future. The performance information shown is as of the calendar year ended December 31, 2022. Updated performance information may be obtained on the Thornburg website at Thornburg.com or by calling 1-800-847-0200.

 

Annual Total Returns – Class A Shares

 
2013 15.35%
2014 -5.90%
2015 6.26%
2016 -2.74%
2017 24.98%
2018 -20.05%
2019 28.66%
2020 22.36%
2021 7.26%
2022 -17.01%
   

 

Total
Returns

Quarter
ended

Highest Quarterly Results

18.62

12/31/2022

Lowest Quarterly Results

-19.54

3/31/2020

The sales charge for Class A shares is not reflected in the returns shown in the bar chart above, and the returns would be less if the charge was taken into account.

Average Annual Total Returns

(periods ended 12-31-22)

Class A Shares

1 Year

5 Years

10 Years

Return Before Taxes

-20.76

1.37

4.14

Return After Taxes on Distributions

-21.30

-0.22

2.12

Return After Taxes on Distributions and Sale of Fund Shares

-12.29

0.73

2.80

MSCI All Country World ex USA Net Total Return USD Index
(reflects no deduction for fees, expenses, or U.S. taxes)

-16.00

0.88

3.80

MSCI EAFE (Europe, Australasia, Far East) Net Total Return USD Index
(reflects no deduction for fees, expenses, or U.S. taxes)

-14.45

1.54

4.67

Class C Shares

1 Year

5 Years

10 Years

Return Before Taxes

-18.41

1.56

3.86

MSCI All Country World ex USA Net Total Return USD Index
(reflects no deduction for fees, expenses, or U.S. taxes)

-16.00

0.88

3.80

MSCI EAFE (Europe, Australasia, Far East) Net Total Return USD Index
(reflects no deduction for fees, expenses, or U.S. taxes)

-14.45

1.54

4.67

THORNBURG INVESTMENT TRUSTPROSPECTUSFEBRUARY 1, 2023

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Fund Summary International Equity Fund

Class I Shares

1 Year

5 Years

10 Years

Return Before Taxes

-16.71

2.63

4.99

MSCI All Country World ex USA Net Total Return USD Index
(reflects no deduction for fees, expenses, or U.S. taxes)

-16.00

0.88

3.80

MSCI Europe, Australasia, Far East Net Total Return USD Index
(reflects no deduction for fees, expenses, or U.S. taxes)

-14.45

1.54

4.67

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 A shares, and after-tax returns for other share classes will vary.

Management

Investment Advisor: Thornburg Investment Management, Inc.

Portfolio Managers:

Lei Wang, cfa, a managing director of Thornburg, has been one of the persons jointly and primarily responsible for management of the Fund since 2006.

Matt Burdett, a managing director of Thornburg, has been one of the persons jointly and primarily responsible for management of the Fund since 2021.

Purchase and Sale of Fund Shares

The minimum amounts for an initial investment in Fund shares and for subsequent investments in Fund shares are shown below. If you purchase your shares through a financial intermediary, the intermediary may impose its own minimum investment requirements. The minimums shown below may also be reduced or waived by the Funds under certain circumstances.

Minimum Initial Investment

Class A

Class C

Class I

Investors Purchasing through a Fee-Based Account with a Financial Intermediary

$2,500

   N/A

    $2,500

Individual Retirement Accounts

$2,000

$2,000

      N/A

All Others

$5,000

$5,000

$2,500,000

Minimum Subsequent Investments (all accounts)

Class A

Class C

Class I

 

  $100

  $100

     $100

The Fund’s shares are redeemable on any business day. If you hold your Fund shares through a financial intermediary, you should contact your intermediary to redeem shares. If you hold your shares directly with the Funds, you may redeem shares at any time by mail (c/o the Fund’s Transfer Agent, SS&C GIDS, Inc., at P.O. Box 219017, Kansas City, Missouri 64121-9017) or by telephone (1-800-847-0200).

Tax Information

Distributions to shareholders will generally be taxable to shareholders as ordinary income or capital gains for federal income tax purposes. Distributions may also be subject to state and local taxes. See “Taxes” on page 158 of the Prospectus.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase shares of a Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund, its investment advisor and/or its distributor may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.

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PROSPECTUSFEBRUARY 1, 2023THORNBURG INVESTMENT TRUST

Fund Summary

Better World International Fund

Investment Goal

The Fund seeks long-term capital appreciation.

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy and hold shares of the Fund. You may qualify for discounts from the sales charges applicable to Class A shares if you or other qualifying account holders invest, or agree to invest in the future, at least $50,000 in the Thornburg Funds. More information about this and other discounts and sales charge waivers is available from your financial intermediary, in the Prospectus under the captions “Class A Sales Charge Waivers,” beginning on page 147, and “Appendix A – Sales Charge Waivers Offered by Financial Intermediaries,” beginning on page 200, and in the Statement of Additional Information under the caption “Additional Information Respecting Purchase and Redemption of Shares,” beginning on page 92.

Shareholder Fees

(fees paid directly from your investment)

 

Class A

Class C

Class I

Maximum Sales Charge (Load) Imposed on Purchases
(as a percentage of offering price)

4.50%

none

none

Maximum Deferred Sales Charge (Load)
(as a percentage of redemption proceeds or original purchase price,
whichever is lower)

none(1)

1.00%(2)

none

Annual Fund Operating Expenses

(expenses that you pay each year as a percentage of the value of your investment)

 

Class A

Class C

Class I

Management Fees

0.98%

0.98%

0.98%

Distribution and Service (12b-1) Fees

0.25%

1.00%

none

Other Expenses

0.35%

0.52%

0.27%

Total Annual Fund Operating Expenses

1.58%

2.50%

1.25%

Fee Waiver/Expense Reimbursement(3)

(0.31)%(3)

(0.35)%(3)

Total Annual Fund Operating Expenses After Fee Waiver/Expense Reimbursement

1.58%

2.19%

0.90%

(1) Up to a 1.00% contingent deferred sales charge (CDSC) is imposed on redemptions of any part or all of a purchase of $1 million or more within 12 months of purchase.
(2) Imposed only on redemptions of Class C shares within 12 months of purchase.
(3) Thornburg Investment Management, Inc. (“Thornburg”) has contractually agreed to waive fees and reimburse expenses incurred by the Fund so that actual Class C and Class I expenses (excluding taxes, interest expenses, 12b-1 distribution and service fees, 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 2.19% and 0.90%, respectively. 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 February 1, 2024, 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.

THORNBURG INVESTMENT TRUSTPROSPECTUSFEBRUARY 1, 2023

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Fund Summary Better World International Fund

Example.

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.

The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem 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 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:

 

1 Year

3 Years

5 Years

10 Years

Class A Shares

$603

$926

$1,272

$2,244

Class C Shares

$322

$749

$1,303

$2,813

Class I Shares

$92

$362

$653

$1,480

You would pay the following expenses if you did not redeem your Class C shares:

 

1 Year

3 Years

5 Years

10 Years

Class C Shares

$222

$749

$1,303

$2,813

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 140.89% of the average value of its portfolio.

Principal Investment Strategies

The Fund pursues its investment goal by investing primarily in a broad range of foreign equity securities or depositary receipts of foreign equity securities. When considering investments for the Fund, the Fund’s investment advisor, Thornburg Investment Management, Inc. (“Thornburg”), combines fundamental research on issuers with analysis of significant environmental, social and governance (“ESG”) characteristics, which Thornburg defines as those ESG factors that may materially affect an issuer’s risk and return profile and, accordingly, the issuer’s long-term investment performance.

The Fund may invest in any stock or other equity security which Thornburg believes may assist the Fund in pursuing its goal, including common stocks, preferred stocks and publicly traded real estate investment trusts. The Fund may invest in companies of any size, but invests primarily in the large and middle capitalization range of publicly traded companies. The Fund may also invest in developing country companies.

Thornburg intends to invest on an opportunistic basis where the Fund’s portfolio managers believe 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, and emerging franchises, when the portfolio managers believe these issues are value priced. The relative proportions of securities invested in each of those categories will vary over time.

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 the advisor had for the company when it was selected for investment, and any such company may not grow or may decline in earnings and size.

 

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PROSPECTUSFEBRUARY 1, 2023THORNBURG INVESTMENT TRUST

Fund Summary Better World International Fund

The Fund’s investments are determined by individual issuer and industry analysis. Investment decisions also include consideration of domestic and international economic developments, outlooks for securities markets, interest rates and inflation, and the supply and demand for securities.

The Fund seeks to invest in companies which in Thornburg’s view are trading at discount to their intrinsic value and also demonstrate one or more significant positive ESG characteristics. Through Thornburg’s fundamental research process, Thornburg evaluates each potential investment based on a variety of factors, including traditional investment criteria such as the company’s ability to effectively allocate capital, willingness to pay dividends and repurchase shares, ability to sustain a competitive advantage, and ability to grow its core business. As part of its research process for the Fund’s investments, Thornburg also assesses each issuer’s ESG characteristics, focusing on those ESG characteristics which Thornburg believes are significant insofar as they are expected to materially affect the issuer’s investment performance. The specific ESG characteristics which Thornburg determines to be significant will vary over time and among different financial sectors and industries, but will generally include the following:

Environmental characteristics, such as an issuer’s emissions and energy management practices;

Social capital characteristics, such as an issuer’s data security and privacy practices;

Human capital characteristics, such as an issuer’s labor practices;

Business model and innovation characteristics, such as an issuer’s supply chain management practices; and

Leadership and governance characteristics, such as an issuer’s practices toward managing legal and regulatory risks.

While Thornburg makes its own judgments about the ESG characteristics of each investment, Thornburg’s approach may be informed by third party data and other research tools, including consideration of the list of material ESG factors established by the Sustainability Accounting Standards Board.

Market observers differ in their perspectives and understanding of the importance of ESG factors to investment decisions. In its evaluation of potential investments, Thornburg may identify as significant certain ESG characteristics that are different from the characteristics that other investors may consider significant. Thornburg consequently may not consider the same ESG characteristics that other investors might consider in evaluating a potential investment. Similarly, Thornburg may assess the significance of ESG characteristics differently than some other investors, assigning either greater or lesser emphasis to a characteristic than another investor might assign.

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.

Principal Investment Risks

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. The value of the Fund’s shares varies from day to day and over time, and when you sell your shares they may be worth less than what you paid for them. The following is a summary of the principal risks of investing in the Fund. The risks are presented in alphabetical order to facilitate readability, and their order does not imply that the realization of one risk is more likely to occur or have a greater adverse impact than another risk. The relative significance of each risk below may change over time.

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.

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.

Developing Country Risk – The risks which may affect investments in foreign issuers (see “Foreign Investment Risk,” below) may be more pronounced for investments in developing countries because the economies of those countries are usually less diversified, communications, transportation and economic infrastructures are less developed, and developing countries ordinarily have less established legal, political, business and social frameworks. At times the prices of equity securities of a developing country issuer may be extremely volatile. An issuer domiciled in a developed country may be similarly affected by these developing country risks to the extent that the issuer conducts its business in developing countries.

 

THORNBURG INVESTMENT TRUSTPROSPECTUSFEBRUARY 1, 2023

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Fund Summary Better World International Fund

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.

ESG Investing Risk – Thornburg’s assessments of company ESG characteristics may result in decisions not to purchase, or to sell, investments which are otherwise consistent with the Fund’s investment goal and subsequently produce attractive investment performance, and Thornburg’s assessments of these characteristics may at times reduce the Fund’s exposure to market sectors or types of investments that produce positive investment performance. The application of ESG principles and the perceptions of the commitment of a given company to ESG principles vary among investors, analysts and other market observers. Consequently, Thornburg’s assessments respecting the ESG characteristics associated with any company may differ from the perceptions of other persons, including other mutual funds. Additionally, it may be difficult in certain instances for Thornburg to evaluate correctly a company’s commitment to positive ESG practices, and a failure to do so may result in investment in companies with practices that are not consistent with the Fund’s aspirations.

Foreign Currency Risk – Fluctuations in currency exchange rates can adversely affect the value of the Fund’s foreign investments. Such fluctuations may occur for a number of reasons, including market and economic conditions, or a government’s decision to devalue its currency or impose currency controls.

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.

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. This risk may be more pronounced for the Fund’s investments in developing countries.

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.

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.

Real Estate Risk – The Fund’s investments in publicly traded real estate investment trusts (“REITs”) are subject to risks affecting real estate investments generally (including market conditions, competition, property obsolescence, changes in interest rates and casualty to real estate), as well as risks specifically affecting REITs (the quality and skill of REIT management and the internal expenses of the REIT).

Redemption Risk – If a significant percentage of the Fund’s shares is owned or controlled by a single shareholder, the Fund is subject to the risk that a redemption by that shareholder of all or a large portion of its shares may require the Fund to sell securities at less than desired prices, and the Fund’s remaining shareholders may also incur additional transaction costs or adverse tax consequences from such trading activity.

Risks Affecting Investments in China – A significant portion of the Fund’s assets may be invested in companies exposed to China. Risks affecting investments in China include a potential downturn in the Chinese economy, reduced liquidity or increased price volatility in the Chinese securities markets as a result of trading suspensions affecting Chinese issuers or other factors, the potential that the Chinese government may expand restrictions on foreign investments or the repatriation of capital, and the implementation of new tariffs or other trade barriers by China or its trading partners. A lack of transparency respecting Chinese companies may also reduce the Fund’s ability to conduct diligence respecting those companies’ accounting and governance standards, which may in turn reduce the Fund’s ability to detect fraudulent practices that may adversely affect the companies’ stock prices.

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

17

PROSPECTUSFEBRUARY 1, 2023THORNBURG INVESTMENT TRUST

Fund Summary Better World International 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.

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.

Small and Mid-Cap Company Risk – Investments in small capitalization companies and mid-capitalization companies may involve additional risks, which may be relatively higher with smaller companies. These additional risks may result from limited product lines, more limited access to markets and financial resources, greater vulnerability to competition and changes in markets, lack of management depth, increased volatility in share price, and possible difficulties in valuing or selling these investments.

Additional information about Fund investments, investment strategies and risks of investing in the Fund appears beginning on page 118 of the Prospectus.

Past Performance of the Fund

The following information provides some indication of the risks of investing in Better World International Fund by showing how the Fund’s investment results vary from year to year. The bar chart shows how the annual total returns for Class A shares of the Fund have been different in each full year shown. The average annual total return figures compare Class A, Class C and Class I share performance to the MSCI All Country World ex USA Net Total Return USD Index, net of withholding taxes on dividends, which is a broad measure of market performance. Past performance (before and after taxes) is not necessarily an indication of how the Fund will perform in the future. The performance information shown is as of the calendar year ended December 31, 2022. Updated performance information may be obtained on the Thornburg website at Thornburg.com or by calling 1-800-847-0200.

 

Annual Total Returns – Class A Shares

 
2016 6.76%
2017 21.88%
2018 -14.28%
2019 23.72%
2020 25.85%
2021 20.39%
2022 -18.48%

 

Total
Returns

Quarter
ended

Highest Quarterly Results

22.85

6/30/2020

Lowest Quarterly Results

-19.58

3/31/2020

The sales charge for Class A shares is not reflected in the returns shown on the bar chart, and the returns would be less if the charge was taken into account.

 

THORNBURG INVESTMENT TRUSTPROSPECTUSFEBRUARY 1, 2023

18

Fund Summary Better World International Fund

Average Annual Total Returns

(periods ended 12-31-22)

Class A Shares

1 Year

5 YEARS

Since
Inception
(10-01-15)

Return Before Taxes

-22.14

4.58

7.55

Return After Taxes on Distributions

-22.23

2.96

5.82

Return After Taxes on Distributions and Sale of Fund Shares

-13.11

3.08

5.33

MSCI All Country World ex USA Net Total Return USD Index
(reflects no deduction for fees, expenses, or U.S. taxes)

-16.00

0.88

5.09

Class C Shares

1 Year

5 YEARS

Since
Inception
(10-01-15)

Return Before Taxes

-19.85

4.88

7.56

MSCI All Country World ex USA Net Total Return USD Index
(reflects no deduction for fees, expenses, or U.S. taxes)

-16.00

0.88

5.09

Class I Shares

1 Year

5 YEARS

Since
Inception
(10-01-15)

Return Before Taxes

-18.01

6.24

8.97

MSCI All Country World ex USA Net Total Return USD Index
(reflects no deduction for fees, expenses, or U.S. taxes)

-16.00

0.88

5.09

After-tax returns are calculated using the historical highest 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 A 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.

Management

Investment Advisor: Thornburg Investment Management, Inc.

Portfolio Manager:

Lei Wang, cfa, a managing director of Thornburg, has been a portfolio manager of the Fund since 2021.

Purchase and Sale of Fund Shares

The minimum amounts for an initial investment in Fund shares and for subsequent investments in Fund shares are shown below. If you purchase your shares through a financial intermediary, the intermediary may impose its own minimum investment requirements. The minimums shown below may also be reduced or waived by the Funds under certain circumstances.

Minimum Initial Investment

Class A

Class C

Class I

Investors Purchasing through a Fee-Based Account with a Financial Intermediary

$2,500

   N/A

    $2,500

Individual Retirement Accounts

$2,000

$2,000

      N/A

All Others

$5,000

$5,000

$2,500,000

19

PROSPECTUSFEBRUARY 1, 2023THORNBURG INVESTMENT TRUST

Fund Summary Better World International Fund

Minimum Subsequent Investments (all accounts)

Class A

Class C

Class I

 

  $100

  $100

     $100

The Fund’s shares are redeemable on any business day. If you hold your Fund shares through a financial intermediary, you should contact your intermediary to redeem shares. If you hold your shares directly with the Funds, you may redeem shares at any time by mail (c/o the Fund’s Transfer Agent, SS&C GIDS, Inc., at P.O. Box 219017, Kansas City, Missouri 64121-9017) or by telephone (1-800-847-0200).

Tax Information

Distributions to shareholders will generally be taxable to shareholders as ordinary income or capital gains for federal income tax purposes. Distributions may also be subject to state and local taxes. See “Taxes” on page 158 of the Prospectus.

Payments to Broker-Dealers and Other Financial Intermediaries

If you purchase shares of a Fund through a broker-dealer or other financial intermediary (such as a bank), the Fund, its investment advisor and/or its distributor may pay the intermediary for the sale of Fund shares and related services. These payments may create a conflict of interest by influencing the broker-dealer or other intermediary and your salesperson to recommend the Fund over another investment. Ask your salesperson or visit your financial intermediary’s website for more information.

THORNBURG INVESTMENT TRUSTPROSPECTUSFEBRUARY 1, 2023

20

Fund Summary

International 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 shares of the Fund. You may qualify for discounts from the sales charges applicable to Class A shares if you or other qualifying account holders invest, or agree to invest in the future, at least $50,000 in the Thornburg Funds. More information about this and other discounts and sales charge waivers is available from your financial intermediary, in the Prospectus under the captions “Class A Sales Charge Waivers,” beginning on page 147, and “Appendix A – Sales Charge Waivers Offered by Financial Intermediaries,” beginning on page 200, and in the Statement of Additional Information under the caption “Additional Information Respecting Purchase and Redemption of Shares,” beginning on page 92.

Shareholder Fees

(fees paid directly from your investment)

 

Class A

Class C

Class I

Maximum Sales Charge (Load) Imposed on Purchases
(as a percentage of offering price)

4.50%

none

none

Maximum Deferred Sales Charge (Load)
(as a percentage of redemption proceeds or original purchase price,
whichever is lower)

none(1)

1.00%(2)

none

Annual Fund Operating Expenses

(expenses that you pay each year as a percentage of the value of your investment)

 

Class A