Strategy. The Fund pursues its investment objective by investing in a broad range of income-producing investments, primarily including debt obligations. The Fund expects, under normal conditions, to invest a majority of its assets in the debt obligations described below. The Fund may invest in debt obligations of any kind, of any quality, and of any maturity. The Fund expects, under normal conditions, to select a majority of its investments from among the following types of debt obligations: ? bonds and other debt obligations issued by domestic and foreign companies of any size; ? below investment grade obligations (sometimes called junk bonds or high yield bonds); ? mortgage-backed securities and other asset-backed securities of private issuers, including commercial mortgage-backed securities, and real … Show more… The Fund pursues its investment objective by investing in a broad range of income-producing investments, primarily including debt obligations. The Fund expects, under normal conditions, to invest a majority of its assets in the debt obligations described below. The Fund may invest in debt obligations of any kind, of any quality, and of any maturity. The Fund expects, under normal conditions, to select a majority of its investments from among the following types of debt obligations: ? bonds and other debt obligations issued by domestic and foreign companies of any size; ? below investment grade obligations (sometimes called junk bonds or high yield bonds); ? mortgage-backed securities and other asset-backed securities of private issuers, including commercial mortgage-backed securities, and real estate mortgage investment conduits; ? obligations issued by foreign governments (including developing countries); ? collateralized mortgage obligations (CMOs), collateralized debt obligations (CDOs), collateralized bond obligations (CBOs), and collateralized loan obligations (CLOs); ? obligations of the U.S. government and its agencies and sponsored enterprises; ? bank loans, loan assignments, loan participants and similar obligations; ? structured notes; ? zero coupon bonds and stripped securities; ? taxable municipal obligations and participations in municipal obligations; and ? convertible debt obligations. The Funds investment adviser, Thornburg, seeks to achieve the Funds investment objective by allocating actively among various market sectors in the fixed income markets, such as those listed above, and through security selection within the selected market sectors. Thornburg allocates the Funds assets among a range of sectors based on strategic positioning and other tactical considerations. In buying and selling investments for the Fund, Thornburg looks for market sectors and securities that it believes will have more favorable relative performance over time. The Fund may invest significantly in one or more sectors, and may at times invest primarily in a single sector, such as asset-backed securities or mortgage-backed securities of private issuers. Thornburg monitors the duration of the Funds portfolio to seek to assess and, in its discretion, adjust the Funds exposure to interest rate risk. Thornburg seeks to manage the Funds duration based on Thornburgs view of, among other things, future interest rates and market conditions. The Fund may use derivative instruments of any kind, including U.S. Treasury futures contracts, to manage the Funds duration. While Thornburg has broad discretion to modify the Funds duration within a wide range in the Advisers discretion and based on its view of market conditions, Thornburg will typically seek to construct an investment portfolio for the Fund with a dollar-weighted average effective duration of one to five years. The effective duration of the Funds portfolio may vary significantly from time to time due to changes in overall market conditions, including changes in the rate of pre-payment speeds, among other reasons, and may be outside the stated range at any time. Duration is a measure of the expected life of a fixed income instrument that is used to determine the sensitivity of a securitys price to changes in interest rates. Effective duration is a measure of the Funds portfolio duration adjusted for the anticipated effect of interest rate changes on bond and mortgage prepayment rates as determined by Thornburg and may vary significantly from time to time. The Fund may invest in obligations of any credit quality and, depending on market conditions and Thornburgs investment outlook, expects, under normal circumstances, to have approximately 35% of its investments in obligations rated below investment grade (sometimes called junk bonds or high yield bonds) or, if unrated, obligations of issuers which Thornburg determines to have comparable below investment grade obligations outstanding or obligations of comparable credit quality to obligors with outstanding below investment grade obligations. The Funds exposure to such bonds may vary significantly over time based on Thornburgs views of market conditions, and may, at times, represent less than 35% or 50% or more of the Funds investments. The Fund may enter into derivatives transactions and other instruments of any kind for hedging purposes or otherwise to gain, or reduce, long or short exposure to one or more asset classes or issuers. For example, the Fund may use futures contracts and options on futures contracts, in order to gain efficient long or short investment exposures as an alternative to cash investments or to hedge against portfolio exposures; interest rate swaps, to gain indirect long or short exposures to interest rates, issuers, or currencies, or to hedge against portfolio exposures; and total return swaps and credit derivatives (such as credit default swaps), put and call options, and exchange-traded and structured notes, to take indirect long or short positions on indexes, securities, currencies, or other indicators of value, or to hedge against portfolio exposures. The Funds 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 debt securities, and analysis of specific issuers. The Fund may not, at the time of purchase, invest more than 25% of its net assets in debt obligations denominated in foreign currencies, but this limitation does not apply to debt obligations issued by foreign issuers and denominated in U.S. dollars. 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 objective. Because the Fund seeks total return, consisting of income and capital appreciation, while also managing risk, the Fund may not obtain the highest yields available. Under normal conditions, the Fund invests at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in debt obligations, income-producing instruments, or investments that provide exposure to debt obligations or income-producing instruments. The Funds 80% policy may be changed by the Funds Trustees without a shareholder vote upon 60 days notice to shareholders. The Fund is classified as a non-diversified fund and may invest in a smaller number of issuers and have a greater percentage of its assets in those issuers than a diversified investment company. Show less