Under normal market conditions, the fund invests at least 80% of its net assets, plus borrowings for investment purposes, in investment grade fixed income securities. Corporate debt securities, including notes, bonds, debentures and commercial paper, are fixed income securities usually issued by businesses to finance their operations. These securities may be secured or unsecured, may be issued by U.S. or foreign entities and may carry variable or floating rates of interest. The fund may invest in Rule 144A securities. The fund may also invest in other short-duration fixed-income securities, such as floating rate loans and structured debt and in cash or cash equivalents such as money market securities. Securities in which the fund will invest will be U.S. dollar-denominated although they may be issued by a foreign corporation or a U.S. affiliate of a foreign corporation, or a foreign government or its agencies and instrumentalities. Although the fund may invest in securities of any maturity, the fund will normally maintain an effective duration, as estimated by the subadviser, of three years or less. Effective duration seeks to measure the expected sensitivity of market price to changes in interest rates, taking into account the anticipated effects of structural complexities (for example, some bonds can be prepaid by the issuer).