Strategy. The Adviser allocates a portion of the Portfolio to a capital appreciation and income component (the "Capital Appreciation and Income Component") managed by BlackRock Investment Management, LLC ("BlackRock" or a "Sub-Adviser") and a portion to a managed risk component (the "Managed Risk Component") managed by Milliman Financial Risk Management LLC ("Milliman" or a "Sub-Adviser"). BlackRock manages the Capital Appreciation and Income Component pursuant to a strategy that seeks to invest in a combination of iShares Exchange Traded Funds ("ETFs") that are affiliated with BlackRock and are offered through different prospectuses. The Portfolio intends its strategy of providing exposure to a combination of ETFs to result in investment diversification that an investor could otherwise achieve only by holding numerous individual investments. … Show more… The Adviser allocates a portion of the Portfolio to a capital appreciation and income component (the "Capital Appreciation and Income Component") managed by BlackRock Investment Management, LLC ("BlackRock" or a "Sub-Adviser") and a portion to a managed risk component (the "Managed Risk Component") managed by Milliman Financial Risk Management LLC ("Milliman" or a "Sub-Adviser"). BlackRock manages the Capital Appreciation and Income Component pursuant to a strategy that seeks to invest in a combination of iShares Exchange Traded Funds ("ETFs") that are affiliated with BlackRock and are offered through different prospectuses. The Portfolio intends its strategy of providing exposure to a combination of ETFs to result in investment diversification that an investor could otherwise achieve only by holding numerous individual investments. Milliman manages the Managed Risk Component pursuant to a strategy that seeks to manage portfolio volatility and provide downside risk management. The Adviser seeks to achieve the Portfolio's investment objective by allocating, under normal circumstances, at least 80% of the Portfolio's net assets, plus any borrowings for investment purposes, to the Capital Appreciation and Income Component and up to 20% of the Portfolio's net assets to the Managed Risk Component. BlackRock expects to further allocate approximately 85% of the Capital Appreciation and Income Component assets to equity-based ETFs, and approximately 15% to fixed-income-based ETFs, although BlackRock may modify the target allocation from time to time. The Portfolio incorporates a global tactical asset allocation strategy that, under normal circumstances, seeks to adjust allocations to asset classes that BlackRock deems to be attractive investments over the short to intermediate term. This strategy seeks to enhance the total return and manages portfolio risk at the aggregate level. Modifications in the allocations to the ETFs are based on techniques that may include technical, qualitative, quantitative and momentum analysis of the market. The mix of ETFs will vary with market conditions and BlackRock's assessment of the ETFs' relative attractiveness as investment opportunities. The ETFs' investments will focus on investments in securities listed on domestic and foreign equity exchanges with growth and value styles, including, small-, mid- and large-cap issuers, and on investments in domestic and foreign fixed-income instruments including U.S. treasuries, mortgage- and asset-backed securities, corporate loans, distressed securities, inflation-indexed instruments, corporate bonds, sovereign and emerging market debt. An ETF may invest a large percentage of its assets in indices located in a single country, a small number of countries, or a particular geographic region. As a result of its exposure to the ETFs, the Portfolio indirectly provides exposure principally to U.S. and non-U.S. equity and fixed-income securities and derivatives. In addition, the ETFs may invest in debt assets in lower quality debt securities (rated Ba1 or below and BB+ or below by Nationally Recognized Statistical Rating Organizations designated by the ETFs' adviser or unrated but determined to be of equivalent quality by the ETFs' adviser). Such securities are sometimes referred to as "junk bonds." An ETF may integrate environmental, social and governance ("ESG") factors into its investment selection process and/or screen out particular companies and industries based on certain ESG related criteria. An ETF may also seek to deliver exposure to certain style factors (i.e., quality, value, momentum, size, minimum volatility). In the Managed Risk Component, the Adviser seeks to manage return volatility by employing Milliman to execute a managed risk strategy, which consists of using hedge instruments to reduce the downside risk of the Portfolio's securities. Milliman may use hedge instruments to accomplish this goal, which may include: equity futures contracts, treasury futures contracts, currency futures contracts, and other hedge instruments judged by Milliman to be necessary to achieve the goals of the managed risk strategy. Milliman may also buy or sell hedge instruments based on one or more market indices in an attempt to maintain the Portfolio's volatility at the targeted level in an environment in which Milliman expects market volatility to decrease or increase, respectively. Milliman selects individual hedge instruments that it believes will have prices that are highly correlated to the Portfolio's positions. Milliman adjusts hedge instruments to manage overall net Portfolio risk exposure, in an attempt to stabilize the volatility of the Portfolio around a predetermined target level and reduce the potential for portfolio losses during periods of significant and sustained market decline. Milliman seeks to monitor and forecast volatility in the markets using a proprietary model, and adjust the Portfolio's hedge instruments accordingly. In addition, Milliman will monitor liquidity levels of relevant hedge instruments and transparency provided by exchanges or counterparties in hedging transactions. Milliman adjusts futures positions to manage overall net Portfolio risk exposure. Milliman may, during periods of rising security prices, implement strategies to preserve gains on the Portfolio's positions. Milliman may, during periods of falling security prices, implement additional strategies to reduce losses in adverse market conditions. In these situations, Milliman's activity could significantly reduce the Portfolio's net economic exposure to equity securities. Following market declines, a downside rebalancing strategy will be used to decrease the amount of hedge instruments used to hedge the Portfolio. Milliman also adjusts hedge instruments to realign individual hedges when the Adviser rebalances the Portfolio's asset allocation profile. Depending on market conditions, scenarios may occur where the Portfolio has no positions in any hedge instruments. Show less