Strategy. Thornburg Investment Management Inc. (Thornburg) actively manages the Funds holdings in pursuing the Funds investment goal. While Thornburg follows domestic and international economic developments, outlooks for securities markets, interest rates and inflation, the supply and demand for debt obligations, and other factors, the Funds investments are determined by individual security analysis. The Fund ordinarily acquires and holds securities for investment rather than for realization of gains by short-term trading on market fluctuations. However, it may dispose of any security prior to its scheduled maturity to enhance income or reduce loss, to change the portfolios average duration or average maturity, or to otherwise respond to current market conditions. Under normal conditions, the Fund invests at least 80% of its net assets, … Show more… Thornburg Investment Management Inc. (Thornburg) actively manages the Funds holdings in pursuing the Funds investment goal. While Thornburg follows domestic and international economic developments, outlooks for securities markets, interest rates and inflation, the supply and demand for debt obligations, and other factors, the Funds investments are determined by individual security analysis. The Fund ordinarily acquires and holds securities for investment rather than for realization of gains by short-term trading on market fluctuations. However, it may dispose of any security prior to its scheduled maturity to enhance income or reduce loss, to change the portfolios average duration or average maturity, or to otherwise respond to current market conditions. Under normal conditions, the Fund invests at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in (i) obligations of the U.S. government, its agencies and instrumentalities, and (ii) debt obligations rated at the time of purchase in one of the four highest ratings of S&P Global Ratings (AAA, AA, A, or BBB) or Moodys Investors Services, Inc. (Aaa, Aa, A, or Baa) or, if no credit rating is available, judged to be of comparable quality by Thornburg. The Fund may purchase corporate debt, municipal securities, and short-term commercial paper and bankers acceptances, and the Fund may also purchase securities backed by an underlying pool of debt obligations, including mortgage-backed securities, asset-backed securities, collateralized mortgage obligations, and collateralized debt obligations (sometimes referred to collectively as structured products). The Fund may purchase foreign securities of the same types and quality as the domestic securities it purchases when Thornburg anticipates foreign securities offer more investment potential. The Fund may invest in debt obligations which are rated by S&P Global Ratings or Moodys Investors Services, Inc. at the time of purchase as below investment grade (commonly referred to as junk or high yield bonds) or, if no credit rating is available, are judged to be of comparable quality by Thornburg, but such investments will be less than 20% of the Funds net assets under normal conditions. Because the magnitude of changes in the value of interest-bearing obligations is greater for obligations with longer durations given an equivalent change in interest rates, the Fund seeks to reduce changes in its share value compared to longer duration fixed income portfolios by maintaining a portfolio of investments with a dollar-weighted average duration of normally no more than one half (0.5) of a year. Duration is a measure of estimated sensitivity to interest rate changes, and a debt obligation or a portfolio of obligations with a higher duration will typically be more sensitive to interest rate changes than an obligation or a portfolio with a lower duration. Duration is commonly expressed as a number, which is the expected percentage change in an obligations price upon a 1% change in interest rates. For example, an obligation with a duration of 0.5 would be expected to change in price by approximately 0.5% in response to a 1% change in interest rates. There is no limitation on the duration or maturity of any specific security the Fund may purchase, and the Fund may sell any security before it matures. The Fund also attempts to reduce changes in share value through credit analysis, selection, and diversification. The Fund ordinarily acquires and holds securities for investment rather than for realization of gains by short-term trading on market fluctuations. However, it may sell an investment prior to its scheduled maturity date to enhance income or reduce loss, to change the portfolios average duration or average maturity, to pursue other investment opportunities, in response to changes in the conditions or business of the investments issuer or changes in overall market conditions, or if, in Thornburgs opinion, the investment no longer serves to achieve the Funds investment goals. The objective of preserving capital may prevent the Fund from obtaining the highest yields available. Show less