Under normal market conditions, the Fund intends to achieve its investment objective by investing at least 80 percent of its net assets in a portfolio of U.S. dollar-denominated fixed- and variable-rate debt securities, including securities issued or guaranteed by the U.S. government or its agencies, instrumentalities or U.S. government-sponsored entities, residential and commercial mortgage-backed securities, asset-backed securities, U.S. corporate bonds, fixed income securities issued by non-U.S. corporations and governments, municipal obligations, privately issued securities and other debt securities bearing fixed or floating interest rates. The Fund may also invest in money market securities.