Strategy. Thornburg Investment Management, Inc. (Thornburg or the Adviser), the Funds investment adviser, actively manages the Funds portfolio in pursuing the Funds investment objective. 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 or investments that provide exposure to such debt obligations. The Fund may invest up to 25% of its net assets in debt obligations which, at the time of purchase, are rated by a nationally recognized statistical rating organization as below investment grade (sometimes called junk bonds or high yield bonds) or, if unrated, are issued by obligors which Thornburg determines to have comparable below investment grade obligations outstanding or to be comparable … Show more… Thornburg Investment Management, Inc. (Thornburg or the Adviser), the Funds investment adviser, actively manages the Funds portfolio in pursuing the Funds investment objective. 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 or investments that provide exposure to such debt obligations. The Fund may invest up to 25% of its net assets in debt obligations which, at the time of purchase, are rated by a nationally recognized statistical rating organization as below investment grade (sometimes called junk bonds or high yield bonds) or, if unrated, are issued by obligors which Thornburg determines to have comparable below investment grade obligations outstanding or to be comparable to obligors with outstanding below investment grade obligations. The Fund may invest in obligations of foreign or domestic issuers, but expects to invest primarily in obligations of domestic issuers under normal circumstances. The Fund may invest in foreign issuers and debt obligations denominated in foreign currencies, as described herein, when the portfolio management team believes conditions for such debt are favorable relative to similar obligations denominated in U.S. dollars. 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 does not expect to invest, at the time of purchase, more than 15% of its net assets in debt obligations issued by issuers in emerging markets, also known as developing countries. There is no limitation on the duration or maturity of any specific debt obligation the Fund may purchase. 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 generally seek to construct a portfolio of investments with a dollar-weighted average duration that falls within two years of the dollar-weighted average duration of the Funds benchmark index, the Bloomberg U.S. Aggregate Bond Index. The 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 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. While the Fund may invest in debt obligations of any type, the Fund will typically invest in the following types of debt obligations: ? corporate debt obligations from domestic and foreign issuers (including developing markets) of any market capitalization; ? below investment grade obligations (sometimes called junk bonds or high yield bonds); ? obligations issued or guaranteed by U.S. and non-U.S. governments and their agencies or instrumentalities; ? mortgage-backed and asset-backed securities, including residential or commercial mortgage-backed securities, collateralized mortgage obligations, issued by agencies of the U.S. government or issued by private entities, or real estate mortgage investment conduits; and ? bank loans, loan assignments, loan participants and similar obligations. 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. Each of the Funds investments is determined by individual issuer and industry analysis, including Thornburgs evaluation, based on, among other things, proprietary or third-party analysis and reports, of domestic and international economic developments, outlooks for securities markets, interest rates and inflation, and the supply and demand for debt obligations. 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 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. The Funds policy of investing at least 80% of its net assets, plus the amount of any borrowings for investment purposes, in debt obligations 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