Share Class

AVERAGE ANNUAL TOTAL RETURNS

YTD 1-YR 3-YR 5-YR INCEPTION*
A Shares (THDAX)
Without sales charge30.01%21.43%2.47%5.42%7.14%
With sales charge24.16%15.99%0.91%4.46%6.51%
Benchmark
MSCI Emerging Markets Index32.26%26.45%5.70%4.83%4.27%
YTD 1-YR 3-YR 5-YR INCEPTION*
C Shares (THDCX)
Without sales charge29.22%20.55%1.70%4.63%6.38%
With sales charge28.22%19.55%1.70%4.63%6.38%
Benchmark
MSCI Emerging Markets Index32.26%26.45%5.70%4.83%4.27%
YTD 1-YR 3-YR 5-YR INCEPTION*
I Shares (THDIX)30.44%21.98%2.93%5.89%7.68%
Benchmark
MSCI Emerging Markets Index32.26%26.45%5.70%4.83%4.27%
YTD 1-YR 3-YR 5-YR INCEPTION*
R5 Shares (THDRX)30.41%21.92%2.93%5.86%7.49%
Benchmark
MSCI Emerging Markets Index32.26%26.45%5.70%4.83%4.27%
YTD 1-YR 3-YR 5-YR INCEPTION*
R6 Shares (TDWRX)30.54%22.08%3.02%5.97%7.60%
Benchmark
MSCI Emerging Markets Index32.26%26.45%5.70%4.83%4.27%
YTD 1-YR 3-YR 5-YR INCEPTION*
A Shares (THDAX)
Without sales charge27.00%17.58%2.49%5.00%6.89%
With sales charge21.29%12.29%0.92%4.03%6.27%
Benchmark
MSCI Emerging Markets Index27.78%22.46%4.90%3.99%3.86%
YTD 1-YR 3-YR 5-YR INCEPTION*
C Shares (THDCX)
Without sales charge26.28%16.65%1.70%4.20%6.13%
With sales charge25.28%15.65%1.70%4.20%6.13%
Benchmark
MSCI Emerging Markets Index27.78%22.46%4.90%3.99%3.86%
YTD 1-YR 3-YR 5-YR INCEPTION*
I Shares (THDIX)27.35%18.06%2.93%5.46%7.43%
Benchmark
MSCI Emerging Markets Index27.78%22.46%4.90%3.99%3.86%
YTD 1-YR 3-YR 5-YR INCEPTION*
R5 Shares (THDRX)27.31%18.06%2.93%5.42%7.24%
Benchmark
MSCI Emerging Markets Index27.78%22.46%4.90%3.99%3.86%
YTD 1-YR 3-YR 5-YR INCEPTION*
R6 Shares (TDWRX)27.39%18.16%3.03%5.53%7.35%
Benchmark
MSCI Emerging Markets Index27.78%22.46%4.90%3.99%3.86%

Returns for less than one year are not annualized.
*Inception date for Class A Shares 12/16/2009.

Returns for less than one year are not annualized.
*Inception date for Class C Shares 12/16/2009.

Returns for less than one year are not annualized.
*Inception date for Class I Shares 12/16/2009.

Returns for less than one year are not annualized.
*Since 12/16/2009. Prior to inception of class R5 (2/1/2013), the performance includes actual returns of class A shares adjusted for class R5 expenses.

Returns for less than one year are not annualized.
*Since 12/16/2009. Prior to inception of class R6 (2/1/2013), the performance includes actual returns of class A shares adjusted for class R6 expenses.

Performance data shown represents past performance and is no guarantee of future results. Investment return and principal value will fluctuate so shares, when redeemed, may be worth more or less than their original cost. Current performance may be lower or higher than quoted.

The maximum sales charge for the Fund’s A shares is 4.50%.

C shares include a 1% contingent deferred sales charge (CDSC) for the first year only.

There is no up-front sales charge for class I shares.

There is no up-front sales charge for class R shares.

FUND OPERATING EXPENSES — Class A Shares

Gross Annual Operating Expenses (as reported in the most recent Prospectus)1.57%
Actual Annual Operating Expenses (fiscal year to date, as of 9/30/2017)1.52%

Expense Ratios – Expressed as a percentage of total fund assets and include management fees and operating costs. Expense ratios fluctuate over time and the expense ratio in the prospectus may differ from the actual expense ratio. The fund's total return includes the deduction of expenses.

For more detailed information on fund expenses, please see the fund's prospectus.

FUND OPERATING EXPENSES — Class C Shares

Gross Annual Operating Expenses (as reported in the most recent Prospectus)2.34%
Actual Annual Operating Expenses (fiscal year to date, as of 9/30/2017)2.26%

Expense Ratios – Expressed as a percentage of total fund assets and include management fees and operating costs. Expense ratios fluctuate over time and the expense ratio in the prospectus may differ from the actual expense ratio. The fund's total return includes the deduction of expenses.

For more detailed information on fund expenses, please see the fund's prospectus.

FUND OPERATING EXPENSES — Class I Shares

Gross Annual Operating Expenses (as reported in the most recent Prospectus)1.16%
Net Annual Operating Expenses (as reported in the most recent Prospectus)1.09%
Actual Annual Operating Expenses (fiscal year to date, as of 9/30/2017)1.07%

Thornburg Investment Management and/or Thornburg Securities Corporation have contractually agreed to waive fees and reimburse expenses through at least April 10, 2018, so that actual expenses do not exceed the net expense ratio above.

Expense Ratios – Expressed as a percentage of total fund assets and include management fees and operating costs. Expense ratios fluctuate over time and the expense ratio in the prospectus may differ from the actual expense ratio. The fund's total return includes the deduction of expenses.

For more detailed information on fund expenses, please see the fund's prospectus.

FUND OPERATING EXPENSES — Class R5 Shares

Gross Annual Operating Expenses (as reported in the most recent Prospectus)1.75%
Net Annual Operating Expenses (as reported in the most recent Prospectus)1.09%
Actual Annual Operating Expenses (fiscal year to date, as of 9/30/2017)1.08%

Thornburg Investment Management and/or Thornburg Securities Corporation have contractually agreed to waive fees and reimburse expenses through at least April 10, 2018, so that actual expenses do not exceed the net expense ratio above.

Expense Ratios – Expressed as a percentage of total fund assets and include management fees and operating costs. Expense ratios fluctuate over time and the expense ratio in the prospectus may differ from the actual expense ratio. The fund's total return includes the deduction of expenses.

For more detailed information on fund expenses, please see the fund's prospectus.

FUND OPERATING EXPENSES — Class R6 Shares

Gross Annual Operating Expenses (as reported in the most recent Prospectus)1.17%
Net Annual Operating Expenses (as reported in the most recent Prospectus)0.99%
Actual Annual Operating Expenses (fiscal year to date, as of 9/30/2017)0.97%

Thornburg Investment Management and/or Thornburg Securities Corporation have contractually agreed to waive fees and reimburse expenses through at least April 10, 2018, so that actual expenses do not exceed the net expense ratio above.

Expense Ratios – Expressed as a percentage of total fund assets and include management fees and operating costs. Expense ratios fluctuate over time and the expense ratio in the prospectus may differ from the actual expense ratio. The fund's total return includes the deduction of expenses.

For more detailed information on fund expenses, please see the fund's prospectus.

MORNINGSTAR RATING

Overall Morningstar Rating among 637 Diversified Emerging Mkts funds, based on risk-adjusted returns for class A shares, using a weighted average of the fund's three- and five-year ratings: respectively, 2 stars and 4 stars among 637 and 452 funds, as of 10/31/2017.

Additional Rating and Ranking Information

To determine a fund's Morningstar Rating™, funds and other managed products with at least a three-year history are ranked in their categories by their Morningstar Risk-Adjusted Return scores. The top 10% receive 5 stars; the next 22.5%, 4 stars; the middle 35%, 3 stars; the next 22.5%, 2 stars; and the bottom 10% receive 1 star. The Risk-Adjusted Return accounts for variation in a managed product's monthly excess performance (excluding sales charges), placing more emphasis on downward variations and rewarding consistent performance. Other share classes may have different performance characteristics. © 2017 Morningstar, Inc. All Rights Reserved. The information contained herein: (1) is proprietary to Morningstar and/or its content providers; (2) may not be copied or distributed; and (3) is not warranted to be accurate, complete or timely. Neither Morningstar nor its content providers are responsible for any damages or losses arising from any use of this information. Past performance is no guarantee of future results.

MORNINGSTAR RATING

Overall Morningstar Rating among 637 Diversified Emerging Mkts funds, based on risk-adjusted returns for class C shares, using a weighted average of the fund's three- and five-year ratings: respectively, 2 stars and 3 stars among 637 and 452 funds, as of 10/31/2017.

Additional Rating and Ranking Information

To determine a fund's Morningstar Rating™, funds and other managed products with at least a three-year history are ranked in their categories by their Morningstar Risk-Adjusted Return scores. The top 10% receive 5 stars; the next 22.5%, 4 stars; the middle 35%, 3 stars; the next 22.5%, 2 stars; and the bottom 10% receive 1 star. The Risk-Adjusted Return accounts for variation in a managed product's monthly excess performance (excluding sales charges), placing more emphasis on downward variations and rewarding consistent performance. Other share classes may have different performance characteristics. © 2017 Morningstar, Inc. All Rights Reserved. The information contained herein: (1) is proprietary to Morningstar and/or its content providers; (2) may not be copied or distributed; and (3) is not warranted to be accurate, complete or timely. Neither Morningstar nor its content providers are responsible for any damages or losses arising from any use of this information. Past performance is no guarantee of future results.

MORNINGSTAR RATING

Overall Morningstar Rating among 637 Diversified Emerging Mkts funds, based on risk-adjusted returns for class I shares, using a weighted average of the fund's three- and five-year ratings: respectively, 2 stars and 4 stars among 637 and 452 funds, as of 10/31/2017.

Additional Rating and Ranking Information

To determine a fund's Morningstar Rating™, funds and other managed products with at least a three-year history are ranked in their categories by their Morningstar Risk-Adjusted Return scores. The top 10% receive 5 stars; the next 22.5%, 4 stars; the middle 35%, 3 stars; the next 22.5%, 2 stars; and the bottom 10% receive 1 star. The Risk-Adjusted Return accounts for variation in a managed product's monthly excess performance (excluding sales charges), placing more emphasis on downward variations and rewarding consistent performance. Other share classes may have different performance characteristics. © 2017 Morningstar, Inc. All Rights Reserved. The information contained herein: (1) is proprietary to Morningstar and/or its content providers; (2) may not be copied or distributed; and (3) is not warranted to be accurate, complete or timely. Neither Morningstar nor its content providers are responsible for any damages or losses arising from any use of this information. Past performance is no guarantee of future results.

MORNINGSTAR RATING

Overall Morningstar Rating among 637 Diversified Emerging Mkts funds, based on risk-adjusted returns for class R5 shares, using a weighted average of the fund's three- and five-year ratings: respectively, 2 stars and 4 stars among 637 and 452 funds, as of 10/31/2017.

Additional Rating and Ranking Information

To determine a fund's Morningstar Rating™, funds and other managed products with at least a three-year history are ranked in their categories by their Morningstar Risk-Adjusted Return scores. The top 10% receive 5 stars; the next 22.5%, 4 stars; the middle 35%, 3 stars; the next 22.5%, 2 stars; and the bottom 10% receive 1 star. The Risk-Adjusted Return accounts for variation in a managed product's monthly excess performance (excluding sales charges), placing more emphasis on downward variations and rewarding consistent performance. Other share classes may have different performance characteristics. © 2017 Morningstar, Inc. All Rights Reserved. The information contained herein: (1) is proprietary to Morningstar and/or its content providers; (2) may not be copied or distributed; and (3) is not warranted to be accurate, complete or timely. Neither Morningstar nor its content providers are responsible for any damages or losses arising from any use of this information. Past performance is no guarantee of future results.

MORNINGSTAR RATING

Overall Morningstar Rating among 637 Diversified Emerging Mkts funds, based on risk-adjusted returns for class R6 shares, using a weighted average of the fund's three- and five-year ratings: respectively, 3 stars and 4 stars among 637 and 452 funds, as of 10/31/2017.

Additional Rating and Ranking Information

To determine a fund's Morningstar Rating™, funds and other managed products with at least a three-year history are ranked in their categories by their Morningstar Risk-Adjusted Return scores. The top 10% receive 5 stars; the next 22.5%, 4 stars; the middle 35%, 3 stars; the next 22.5%, 2 stars; and the bottom 10% receive 1 star. The Risk-Adjusted Return accounts for variation in a managed product's monthly excess performance (excluding sales charges), placing more emphasis on downward variations and rewarding consistent performance. Other share classes may have different performance characteristics. © 2017 Morningstar, Inc. All Rights Reserved. The information contained herein: (1) is proprietary to Morningstar and/or its content providers; (2) may not be copied or distributed; and (3) is not warranted to be accurate, complete or timely. Neither Morningstar nor its content providers are responsible for any damages or losses arising from any use of this information. Past performance is no guarantee of future results.

Dividends and Capital Gains — Class A Shares

Dividend (paid Sep 22, 2017)$0.05900
Capital Gains (2017)None Paid

Dividends and Capital Gains — Class C Shares

Dividend (paid Sep 22, 2017)$0.02418
Capital Gains (2017)None Paid

Dividends and Capital Gains — Class I Shares

Dividend (paid Sep 22, 2017)$0.08000
Capital Gains (2017)None Paid

Dividends and Capital Gains — Class R5 Shares

Dividend (paid Sep 22, 2017)$0.08013
Capital Gains (2017)None Paid

Dividends and Capital Gains — Class R6 Shares

Dividend (paid Sep 22, 2017)$0.08403
Capital Gains (2017)None Paid

HYPOTHETICAL GROWTH OF $10,000 as of 10/31/2017(Thornburg Developing World Fund vs. MSCI Emerging Markets Index)

  • A shares with sales charge$16,432
  • MSCI Emerging Markets Index$13,898
The Hypothetical Growth of $10,000 graph compares a hypothetical $10,000 investment in the Fund to the performance of the Index for the stated time period. Returns reflect reinvestment of dividends and capital gains, if any, as well as all fees and expenses.

HYPOTHETICAL GROWTH OF $10,000 as of 10/31/2017(Thornburg Developing World Fund vs. MSCI Emerging Markets Index)

  • C shares$16,269
  • MSCI Emerging Markets Index$13,898
The Hypothetical Growth of $10,000 graph compares a hypothetical $10,000 investment in the Fund to the performance of the Index for the stated time period. Returns reflect reinvestment of dividends and capital gains, if any, as well as all fees and expenses.

HYPOTHETICAL GROWTH OF $10,000 as of 10/31/2017(Thornburg Developing World Fund vs. MSCI Emerging Markets Index)

  • I shares$17,902
  • MSCI Emerging Markets Index$13,898
The Hypothetical Growth of $10,000 graph compares a hypothetical $10,000 investment in the Fund to the performance of the Index for the stated time period. Returns reflect reinvestment of dividends and capital gains, if any, as well as all fees and expenses.

HYPOTHETICAL GROWTH OF $10,000 as of 10/31/2017(Thornburg Developing World Fund vs. MSCI Emerging Markets Index)

  • R5 shares$17,665
  • MSCI Emerging Markets Index$13,898
The Hypothetical Growth of $10,000 graph compares a hypothetical $10,000 investment in the Fund to the performance of the Index for the stated time period. Returns reflect reinvestment of dividends and capital gains, if any, as well as all fees and expenses.

Prior to inception of this share class, performance is calculated from actual returns of the class A shares adjusted for the expenses of the newer share class.

HYPOTHETICAL GROWTH OF $10,000 as of 10/31/2017(Thornburg Developing World Fund vs. MSCI Emerging Markets Index)

  • R6 shares$17,813
  • MSCI Emerging Markets Index$13,898
The Hypothetical Growth of $10,000 graph compares a hypothetical $10,000 investment in the Fund to the performance of the Index for the stated time period. Returns reflect reinvestment of dividends and capital gains, if any, as well as all fees and expenses.

Prior to inception of this share class, performance is calculated from actual returns of the class A shares adjusted for the expenses of the newer share class.

Important Information
Before investing, carefully consider the Fund’s investment goals, risks, charges, and expenses. For a prospectus or summary prospectus containing this and other information, contact your financial advisor or visit our literature center. Read them carefully before investing.

Investments carry risks, including possible loss of principal. Additional risks may be associated with investments outside the United States, especially in emerging markets, including currency fluctuations, illiquidity, volatility, and political and economic risks. Investments in small- and mid-capitalization companies may increase the risk of greater price fluctuations. Investments in the Fund are not FDIC insured, nor are they bank deposits or guaranteed by a bank or any other entity.

The performance of any index is not indicative of the performance of any particular investment. Unless otherwise noted, index returns reflect the reinvestment of income dividends and capital gains, if any, but do not reflect fees, brokerage commissions or other expenses of investing. Investors may not make direct investments into any index.

Diversification does not assure or guarantee better performance and cannot eliminate the risk of investment losses.

Class R shares are limited to retirement platforms only.

Class I shares may not be available to all investors. Minimum investments for the I share class may be higher than those for other classes.

There is no guarantee that the Fund will meet its investment objectives.

Please see our glossary for a definition of terms.

Thornburg mutual funds are distributed by Thornburg Securities Corporation.

Thornburg Investment Management, Inc. mutual funds are sold through investment professionals including investment advisors, brokerage firms, bank trust departments, trust companies and certain other financial intermediaries. Thornburg Securities Corporation (TSC) does not act as broker of record for investors.