Under normal market conditions, the Fund invests at least 80% of its net assets in bonds of U.S. issuers, including government, corporate debt, mortgage-backed and asset-backed securities. Bonds include debt obligations of any maturity, such as bonds, notes, bills and debentures. 'U.S. issuers' include entities, whose securities are listed or traded principally on a recognized stock exchange or over-the-counter market in the U.S., that derive 50% or more of their total revenue from either goods or services produced or sales made in the U.S., that have 50% or more of their assets in the U.S. or that are organized under the laws of, or with principal offices in, the U.S.