Under normal market conditions, the Fund invests at least 80% of its net assets (including the amount of any borrowings for investment purposes) in bonds and other debt securities, including debt securities issued by the U.S. Government, its agencies, instrumentalities or sponsored corporations, debt securities issued by corporations, mortgage- and other asset-backed securities, dollar-denominated securities issued by foreign governments, companies or other entities, bank loans and other obligations. Other obligations include any other security or instrument in which there is a requirement or obligation to repay money borrowed. For purposes of its 80% test, the Fund treats investment in loans as “debt securities,” even though loans may not be “securities” under certain of the federal securities laws. The Fund may invest up to 20% of its net assets in debt instruments that, at the time of purchase, are rated below investment grade or are unrated but determined to be of comparable quality (commonly referred to as “high-yield” investments or “junk” bonds). The Fund may invest in fixed income securities of any maturity and does not seek to maintain a particular dollar-weighted average maturity or duration at the Fund level. 

Up to 25% of the Fund's net assets may be invested in foreign investments (including in emerging markets), which may include investments of up to 20% of the Fund’s assets in non-U.S. dollar denominated securities. In connection with its strategy relating to foreign investments, the Fund may buy or sell foreign currencies in lieu of or in addition to non-dollar denominated fixed-income securities in order to increase or decrease its exposure to foreign interest rate and/or currency markets. 

The Fund may invest in derivatives, including forward contracts (including forward foreign currency contracts), futures contracts (including currency futures, index futures (including fixed income index and volatility index futures), interest rate futures and other bond futures), inverse variable- or floating-rate obligations (commonly referred to as inverse floaters), options (including options on futures contracts and interest rate options), options on swaps (commonly known as swaptions), and swaps (including credit default swaps, credit default swap indexes, interest rate swaps, and total return swaps). The Fund may use derivatives in an effort to produce incremental earnings, to hedge existing positions, to increase market or credit exposure and investment flexibility (including using the derivative as a substitute for the purchase or sale of the underlying security, currency or other asset), to manage credit and interest rate exposure, and/or to manage duration and yield curve of the Fund or a sleeve of the Fund. 

The Fund’s investments in mortgage-related securities include investments in stripped mortgage-backed securities such as interest-only (IO) and principal-only (PO) securities. The Fund may also invest in exchange-traded funds (ETFs). 

The Fund may purchase or sell securities on a when-issued, delayed delivery or forward commitment basis. Such securities may include mortgage-backed securities acquired or sold in the “to be announced” (TBA) market and those in a dollar roll transaction. 

The Fund may invest in privately placed and other securities or instruments that are purchased and sold pursuant to Rule 144A or other exemptions under the Securities Act of 1933, as amended, subject to certain regulatory restrictions. 

The Fund may also hold/invest in cash, money market instruments (which may include investments in one or more affiliated or unaffiliated money market funds or similar vehicles) or other high-quality, short-term investments, including for the purpose of covering its obligations with respect to, or that may result from, the Fund’s investments in derivatives. 

Each sleeve manager’s investment strategy may involve the frequent trading of portfolio securities. One or more of the Fund’s subadvisers use quantitative methods to identify investment opportunities and construct their portion of the Fund’s portfolio.