Strategy. Under normal circumstances, the Portfolio invests at least 80% of its net assets, plus borrowings for investment purposes, in securities of companies with medium market capitalizations (or other financial instruments that derive their value from the securities of such companies). For this Portfolio, medium market capitalization companies are those companies with market capitalizations within the range of at least one of the following indices at the time of purchase: Russell Midcap Index (approximately $ 355 million - $175 billion as of December 31, 2024), Morningstar Mid Core Index (approximately $7.56 billion - $ 234 billion as of December 31, 2024), or Standard & Poors MidCap 400 Index (approximately $2.31 billion - $75.61 billion as of December 31, 2024). The size … Show more… Under normal circumstances, the Portfolio invests at least 80% of its net assets, plus borrowings for investment purposes, in securities of companies with medium market capitalizations (or other financial instruments that derive their value from the securities of such companies). For this Portfolio, medium market capitalization companies are those companies with market capitalizations within the range of at least one of the following indices at the time of purchase: Russell Midcap Index (approximately $ 355 million - $175 billion as of December 31, 2024), Morningstar Mid Core Index (approximately $7.56 billion - $ 234 billion as of December 31, 2024), or Standard & Poors MidCap 400 Index (approximately $2.31 billion - $75.61 billion as of December 31, 2024). The size of companies in an index changes with market conditions, which can result in changes to the market capitalization range of companies in the index. The Portfolio may invest up to 10% of its assets in foreign securities. The Portfolios investments may include real estate investment trusts (REITs). The Portfolios assets normally are allocated among three or more investment managers, each of which manages its portion of the Portfolio using a different but complementary investment strategy. One portion of the Portfolio is actively managed (Active Allocated Portion); one portion of the Portfolio seeks to track the performance of a particular index (Index Allocated Portion); and one portion of the Portfolio invests in exchange-traded funds (ETFs) (ETF Allocated Portion). Under normal circumstances, the Active Allocated Portion consists of approximately 30% of the Portfolios net assets, the Index Allocated Portion consists of approximately 60% of the Portfolios net assets, and the ETF Allocated Portion consists of approximately 10% of the Portfolios net assets. These percentages are targets established by the Adviser; actual allocations may deviate from these targets. The Active Allocated Portion utilizes a value-oriented investment style and invests primarily in equity securities of companies that, in the view of the Sub-Advisers, are currently under-valued according to certain financial measurements, which may include price-to-earnings and price-to-book ratios and dividend income potential. A Sub-Adviser may sell a security for a variety of reasons, such as because it becomes overvalued or shows deteriorating fundamentals, or to invest in a company believed by the Sub-Adviser to offer superior investment opportunities. The Index Allocated Portion seeks to track the performance (before fees and expenses) of the Russell Midcap Value Index with minimal tracking error. This strategy is commonly referred to as an indexing strategy. Generally, the Index Allocated Portion uses a full replication technique, although in certain instances a sampling approach may be utilized for a portion of the Index Allocated Portion. The Index Allocated Portion also may invest in other instruments, such as futures and options contracts, that provide comparable exposure as the index without buying the underlying securities comprising the index. The Adviser also may utilize futures and options, such as exchange-traded futures and options contracts on securities indices, to manage equity exposure. Futures and options can provide exposure to the performance of a securities index without buying the underlying securities comprising the index. They also provide a means to manage the Portfolios equity exposure without having to buy or sell securities. When market volatility is increasing above specific thresholds set for the Portfolio, the Adviser may limit equity exposure by reducing investments in securities, shorting or selling long futures and options positions on an index, increasing cash levels, and/or shorting an index. During such times, the Portfolios exposure to equity securities may be significantly less than that of a traditional equity portfolio, but may remain sizable. Conversely, when the market volatility indicators decrease, the Adviser may increase equity exposure in the Portfolio such as by investing in futures contracts on an index. During periods of heightened market volatility, the Portfolios exposure to equity securities may remain sizable if, in the Advisers judgment, such exposure is warranted in order to produce better risk-adjusted returns over time. Volatility is a statistical measure of the magnitude of changes in the Portfolios returns, without regard to the direction of those changes. Higher volatility generally indicates higher risk and is often reflected by frequent and sometimes significant movements up and down in value. Volatility management techniques could reduce potential losses and/or mitigate financial risks to insurance companies that provide certain benefits and guarantees available under the Contracts and offer the Portfolio as an investment option in their products. Accordingly, volatility management techniques could also benefit the insurance companies by reducing the risk that the insurance companies will be required to pay amounts to meet the benefits and guarantees from their own resources. It is anticipated that the Portfolios derivative instruments will consist primarily of exchange-traded futures and options contracts on securities indices, but the Portfolio also may utilize other types of derivatives. The Portfolios investments in derivatives may be deemed to involve the use of leverage because the Portfolio is not required to invest the full market value of the contract upon entering into the contract but participates in gains and losses on the full contract price. The use of derivatives also may be deemed to involve the use of leverage because the heightened price sensitivity of some derivatives to market changes may magnify the Portfolios gain or loss. It is not generally expected, however, that the Portfolio will be leveraged by borrowing money for investment purposes. The Portfolio may maintain a significant percentage of its assets in cash and cash equivalent instruments, some of which may serve as margin or collateral for the Portfolios obligations under derivative transactions. The ETF Allocated Portion invests in ETFs (the Underlying ETFs) that meet the investment criteria of the Portfolio as a whole. The Underlying ETFs in which the ETF Allocated Portion may invest may be changed from time to time without notice or shareholder approval. Show less