Strategy. Normally, the portfolio invests at least 80% of its net assets (plus the amount of borrowings, if any, for investment purposes) in debt securities issued or guaranteed by the U.S. government, its agencies and instrumentalities, investment grade debt securities (including convertible debt) of corporate or other issuers and cash, cash equivalents and other short-term holdings. Derivative instruments that provide exposure to such securities or have similar economic characteristics may be used to satisfy the portfolios 80% policy. The portfolio may invest a substantial portion of its assets in mortgage-related securities, including commercial mortgage-backed securities, collateralized mortgage obligations, credit risk transfer securities and sub-prime mortgages; and asset-backed securities. The portfolios investments in mortgage-related and asset-backed securities include securities issued by private … Show more… Normally, the portfolio invests at least 80% of its net assets (plus the amount of borrowings, if any, for investment purposes) in debt securities issued or guaranteed by the U.S. government, its agencies and instrumentalities, investment grade debt securities (including convertible debt) of corporate or other issuers and cash, cash equivalents and other short-term holdings. Derivative instruments that provide exposure to such securities or have similar economic characteristics may be used to satisfy the portfolios 80% policy. The portfolio may invest a substantial portion of its assets in mortgage-related securities, including commercial mortgage-backed securities, collateralized mortgage obligations, credit risk transfer securities and sub-prime mortgages; and asset-backed securities. The portfolios investments in mortgage-related and asset-backed securities include securities issued by private issuers. The portfolios investments in mortgage-related securities may include instruments, the underlying assets of which allow for balloon payments (where a substantial portion of a mortgage loan balance is paid at maturity, which can shorten the average life of the mortgage-backed instrument) or negative amortization payments (where as a result of a payment cap, payments on a mortgage loan are less than the amount of principal and interest owed, with excess amounts added to the outstanding principal balance, which can extend the average life of the mortgage-backed instrument). The portfolio also may invest a portion of its assets in subordinated debt securities, municipal securities, preferred securities, Treasury Inflation Protected Securities (TIPS) and other inflation-linked debt securities, floating-rate loans and insurance-linked securities. The portfolio also may enter into mortgage dollar roll transactions. The portfolio may invest up to 20% of its net assets in debt securities rated below investment grade or, if unrated, of equivalent credit quality as determined by the adviser (known as junk bonds), including securities that are in default. The portfolio may invest up to 15% of its total assets in securities of non-U.S. issuers, including up to 5% of its total assets in securities of emerging market issuers. The portfolio may invest in securities of any maturity, and maintains an average portfolio maturity which varies based upon the judgment of the portfolio's adviser. The maturity of a fixed income security is a measure of the time remaining until final payment on the security is due. The portfolio's investments may have fixed or variable principal payments and all types of interest rate payment and reset terms, including fixed rate, floating rate, inverse floating rate, zero coupon, when-issued, delayed delivery, to be announced and forward commitment, contingent, deferred and payment in kind and auction rate features. The portfolio may, but is not required to, use derivatives, such as credit default swaps and credit default swap index products (CDX) (swaps based on a portfolio of credit default swaps with similar characteristics, such as credit default swaps on high-yield bonds). The portfolio may use derivatives for a variety of purposes, including: in an attempt to hedge against adverse changes in the market price of securities, interest rates or currency exchange rates; as a substitute for purchasing or selling securities; to attempt to increase the portfolio's return as a non-hedging strategy that may be considered speculative; to manage portfolio characteristics; and as a cash flow management technique. The portfolio may choose not to make use of derivatives for a variety of reasons, and any use may be limited by applicable law and regulations. The portfolio may hold cash or other short-term investments. The adviser considers both broad economic and issuer specific factors in selecting investments. In assessing the appropriate maturity, credit quality and sector weighting of the portfolio's portfolio, the adviser considers a variety of factors that are expected to influence economic activity and interest rates. The adviser selects individual securities to buy and sell based upon such factors as a securitys yield, liquidity and rating, an assessment of credit quality, and sector and issuer diversification. The adviser integrates environmental, social and corporate governance (ESG) considerations into its investment research process by evaluating the business models and practices of issuers and their ESG-related risks. The adviser believes ESG analysis is a meaningful facet of fundamental research, the process of evaluating an issuer based on its financial position, business operations, competitive standing and management. This process considers ESG information, where available, in assessing an investments performance potential. The adviser generally considers ESG information in the context of an issuers respective sector or industry. The adviser may consider ESG ratings provided by third parties or internal sources, as well as issuer disclosures and public information, in evaluating issuers. ESG considerations are not a primary focus of the portfolio, and the weight given by the adviser to ESG considerations in making investment decisions will vary and, for any specific decision, they may be given little or no weight. Notwithstanding the foregoing, the adviser generally will not invest portfolio assets in companies engaged in the production, sale, storage of, or providing services for, certain controversial weapons, including chemical, biological and depleted uranium weapons and certain antipersonnel mines and cluster bombs. Show less