Strategy. Under normal circumstances, the Fund invests at least 80% of its net assets (including the amount of any borrowings for investment purposes) in municipal securities that pay interest exempt from U.S. federal income tax (including the federal alternative minimum tax (AMT)). These securities are issued by or on behalf of states and their political subdivisions, agencies, authorities and instrumentalities, by other qualified issuers and by funds that invest in such securities. Qualified issuers include issuers located in U.S. territories, commonwealths and possessions, such as Guam, Puerto Rico and the U.S. Virgin Islands. The Fund may invest up to 20% of its net assets in securities that pay interest subject to U.S. federal income tax (including the federal AMT). The Fund … Show more… Under normal circumstances, the Fund invests at least 80% of its net assets (including the amount of any borrowings for investment purposes) in municipal securities that pay interest exempt from U.S. federal income tax (including the federal alternative minimum tax (AMT)). These securities are issued by or on behalf of states and their political subdivisions, agencies, authorities and instrumentalities, by other qualified issuers and by funds that invest in such securities. Qualified issuers include issuers located in U.S. territories, commonwealths and possessions, such as Guam, Puerto Rico and the U.S. Virgin Islands. The Fund may invest up to 20% of its net assets in securities that pay interest subject to U.S. federal income tax (including the federal AMT). The Fund normally invests at least 80% of its total assets in municipal securities that, at the time of purchase, are rated investment grade or are unrated but determined by the management team to be of comparable quality. The Fund may invest up to 10% of its total assets in debt instruments that, at the time of purchase, are rated below investment grade or are unrated but determined to be of comparable quality (commonly referred to as high-yield investments or junk bonds). The Funds portfolio duration normally ranges from three to seven years. The Fund may enter into tender option bond (TOB) transactions and may invest in derivatives, such as floating rate municipal securities (floaters) and inverse floating rate municipal securities (inverse floaters) to add incremental income, futures (including interest rate and Treasury bond futures) to manage duration and hedge against changes in interest rates, and swaps, including Municipal Market Data Rate Locks (MMD Rate Locks) to manage duration and hedge against changes in interest rates. Inverse floaters provide the Fund with leveraged exposure to underlying municipal bonds whose interest payments vary inversely with changes in short-term tax-exempt interest rates. Show less