Strategy. The Fund pursues its objective by investing principally in high-yielding municipal securities that may be non-investment grade or investment grade. As a matter of fundamental policy, the Fund invests, under normal circumstances, at least 80% of its net assets in municipal securities that pay interest that is exempt from U.S. federal income tax. These securities may pay interest that is subject to the U.S. federal alternative minimum tax (AMT) for certain taxpayers. The Adviser selects securities for purchase or sale based on its assessment of the securities risk and return characteristics as well as the securities impact on the overall risk and return characteristics of the Fund. In making this assessment, the Adviser takes into account various factors, including the … Show more… The Fund pursues its objective by investing principally in high-yielding municipal securities that may be non-investment grade or investment grade. As a matter of fundamental policy, the Fund invests, under normal circumstances, at least 80% of its net assets in municipal securities that pay interest that is exempt from U.S. federal income tax. These securities may pay interest that is subject to the U.S. federal alternative minimum tax (AMT) for certain taxpayers. The Adviser selects securities for purchase or sale based on its assessment of the securities risk and return characteristics as well as the securities impact on the overall risk and return characteristics of the Fund. In making this assessment, the Adviser takes into account various factors, including the credit quality and sensitivity to interest rates of the securities under consideration and of the Funds other holdings. The Fund may invest without limit in lower-rated securities (junk bonds), which may include securities having the lowest rating, and in unrated securities that, in the Advisers judgment, would be lower-rated securities if rated. The Fund may invest in fixed-income securities with any maturity or duration. The Fund will seek to increase income for shareholders by investing in longer-maturity bonds. Consistent with its objective of seeking a higher level of income, the Fund may experience greater volatility and a higher risk of loss of principal than other municipal funds. The Fund may also invest in: tender option bond transactions (TOBs); forward commitments; zero-coupon municipal securities and variable, floating and inverse floating-rate municipal securities; certain types of mortgage-related securities; and derivatives, such as options, futures contracts, forwards and swaps. The Fund may make short sales of securities or maintain a short position, and may use other investment techniques. The Fund may use leverage for investment purposes to increase income through the use of TOBs and derivative instruments, such as interest rate swaps. Show less