Strategy. Under normal market conditions, the Fund will invest at least 80% of its net assets (including the amount of any borrowings for investment purposes) in bonds and other debt obligations issued by or on behalf of state or local governmental units whose interest is exempt from federal income tax. The Fund may invest broadly in municipal bond obligations of any duration, maturity and credit quality, including below investment grade (junk) bonds. The Fund may invest up to 20% of its net assets in securities, the income on which is subject to federal income tax and may invest without limit in debt instruments the income on which is subject to the federal alternative minimum tax. The Fund may also invest in … Show more… Under normal market conditions, the Fund will invest at least 80% of its net assets (including the amount of any borrowings for investment purposes) in bonds and other debt obligations issued by or on behalf of state or local governmental units whose interest is exempt from federal income tax. The Fund may invest broadly in municipal bond obligations of any duration, maturity and credit quality, including below investment grade (junk) bonds. The Fund may invest up to 20% of its net assets in securities, the income on which is subject to federal income tax and may invest without limit in debt instruments the income on which is subject to the federal alternative minimum tax. The Fund may also invest in securities of other qualified issuers, including issuers located in U.S. territories, commonwealths and possessions, such as Guam, Puerto Rico and the U.S. Virgin Islands. The Fund may invest in debt instruments of any maturity and does not seek to maintain a particular dollar-weighted average maturity. A bond is issued with a specific maturity date, which is the date when the issuer must pay back the bonds principal (face value). Bond maturities range from less than 1 year to more than 30 years. Typically, the longer a bonds maturity, the more price risk the Fund and the Funds investors face as interest rates rise, but the Fund could receive a higher yield in return for that longer maturity and higher interest rate risk. The Fund may invest in securities of other open-end or closed-end investment companies, including exchange-traded funds and municipal bond money market funds, that invest primarily in the types of debt instruments in which the Fund may invest directly. Given the flexible investment approach of the Fund, its maturity, duration, credit quality and sector allocations may fluctuate in order to achieve its investment objective. 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