Strategy. Under normal market conditions, the Portfolio invests at least 80% of its net assets, plus borrowings for investment purposes, in debt securities. The Portfolio uses a strategy that is commonly referred to as an index strategy. In seeking to achieve the Portfolios investment objective, the Sub-Adviser generally will employ a stratified sampling approach to build a portfolio whose broad characteristics match those of the Corporate Bond Index, which means that the Portfolio is not required to purchase all of the securities represented in the Index. A stratified sampling approach seeks to match the return and characteristics of a particular index without having to purchase every security in that index by selecting a representative sample of securities for the Portfolio based … Show more… Under normal market conditions, the Portfolio invests at least 80% of its net assets, plus borrowings for investment purposes, in debt securities. The Portfolio uses a strategy that is commonly referred to as an index strategy. In seeking to achieve the Portfolios investment objective, the Sub-Adviser generally will employ a stratified sampling approach to build a portfolio whose broad characteristics match those of the Corporate Bond Index, which means that the Portfolio is not required to purchase all of the securities represented in the Index. A stratified sampling approach seeks to match the return and characteristics of a particular index without having to purchase every security in that index by selecting a representative sample of securities for the Portfolio based on the characteristics of the index and the particular securities included therein. With respect to the Corporate Bond Index, such characteristics may include interest rate sensitivity, credit quality and sector diversification. Individual securities holdings may differ from those of the Corporate Bond Index, and the Portfolio may not track the performance of the Index due to expenses and transaction costs, the size and frequency of cash flow into and out of the Portfolio, and differences between how and when the Portfolio and the Index are valued. The Corporate Bond Index measures the performance of U.S. investment grade, taxable corporate bonds with maturities between 5 and 10 years that have $300 million or more of outstanding face value. The securities in the Index must be U.S. dollar-denominated and must be fixed-rate. The Index includes securities publicly issued by U.S. and non-U.S. industrial, utility, and financial companies. The Index is rebalanced monthly, and its components are weighted based on market value, taking into account the component securitys price, accrued interest and par amount outstanding. Securities may be added to or removed from the Index in connection with the month-end rebalancing process. As of December 31, 2024, there were approximately 2,243 securities in the Index. The investment grade securities in the Index are listed and traded on U.S. exchanges and are rated BBB or higher by Standard & Poors Global Ratings (S&P) or Fitch Ratings Ltd. (Fitch) or Baa or higher by Moodys Investors Service, Inc. (Moodys). The Portfolio will normally maintain a dollar-weighted average maturity between 5 and 10 years, which is consistent with that of the Index. The Portfolio will normally maintain an average duration consistent with that of the Index. As of December 31, 2024, the average duration of the Index was 5.96 years. The Portfolio also may invest up to 10% of its assets in exchange-traded funds (ETFs) that seek to track the Corporate Bond Index. Show less