Strategy. Under normal market conditions, the Fund seeks to achieve its investment objective by investing at least 80% of its net assets (including investment borrowings) in municipal debt securities that pay interest that is exempt from regular federal income taxes (collectively, Municipal Securities ). Municipal Securities are generally issued by or on behalf of states, territories or possessions of the U.S. and the District of Columbia and their political subdivisions, agencies, authorities and other instrumentalities. The Funds investment advisor seeks to construct a portfolio that has a weighted average duration of 1 3 years. Duration is a mathematical calculation of the average life of a debt security (or portfolio of debt securities) that serves as a measure of its price risk. … Show more… Under normal market conditions, the Fund seeks to achieve its investment objective by investing at least 80% of its net assets (including investment borrowings) in municipal debt securities that pay interest that is exempt from regular federal income taxes (collectively, Municipal Securities ). Municipal Securities are generally issued by or on behalf of states, territories or possessions of the U.S. and the District of Columbia and their political subdivisions, agencies, authorities and other instrumentalities. The Funds investment advisor seeks to construct a portfolio that has a weighted average duration of 1 3 years. Duration is a mathematical calculation of the average life of a debt security (or portfolio of debt securities) that serves as a measure of its price risk. In general, each year of duration represents an expected 1% change in the value of a security for every 1% immediate change in interest rates. For example, if a portfolio of mortgage loans has an average duration of three years, its value can be expected to fall about 3% if interest rates rise by 1%. Conversely, the portfolios value can be expected to rise about 3% if interest rates fall by 1%. As a result, prices of instruments with shorter durations tend to be less sensitive to interest rate changes than instruments with longer durations. As the value of a security changes over time, so will its duration. The Funds investment advisor will calculate the duration of the portfolio by modeling the cash flows of all the individual holdings, including the impact of prepayment variability and coupon adjustments where applicable, to determine the duration of each holding and then aggregating based on the size of the position. In performing this duration calculation, the Funds investment advisor will utilize third-party models. In selecting the Funds portfolio, the portfolio managers will focus on Municipal Securities that meet basic infrastructure needs or provide critical services within their communities. The Fund will invest in Municipal Securities issued throughout the United States, including in Municipal Securities issued by entities in at least 10 different states, with an emphasis on states with growing populations and healthy employment trends. Under normal market conditions, the Fund will primarily invest in Municipal Securities that are, at the time of investment, rated as investment grade ( i.e. , rated Baa3/BBB- or above) by at least one nationally recognized statistical rating organization ( "NRSRO" ) rating such securities or, if unrated, Municipal Securities determined by the Funds investment advisor to be of comparable quality. The Fund may invest up to 35% of its net assets in Municipal Securities rated below investment grade by at least one NRSRO rating such securities (or Municipal Securities that are unrated and determined by the Funds investment advisor to be of comparable quality), commonly referred to as high yield or junk bonds. Additionally, for newly-issued Municipal Securities, the Fund may consider an expected rating provided by an NRSRO as if it were a final rating. The types of Municipal Securities in which the Fund may invest as a part of its principal investment strategy include municipal general obligation bonds, municipal revenue bonds, alternative minimum tax bonds and private activity bonds (including without limitation industrial development bonds), and pre-refunded and escrowed to maturity bonds. Interest on alternative minimum tax bonds and private activity bonds may be subject to the federal alternative minimum tax on individuals. For tax years beginning after December 31, 2022, interest on the bonds may affect the corporate alternative minimum tax for certain corporations. The Fund may also purchase new issues of Municipal Securities on a when-issued or forward commitment basis. The Municipal Securities in which the Fund invests may be fixed, variable or floating-rate securities. Show less