The BlackRock Mid-Cap Growth Equity Portfolio typically dedicates a substantial portion of its capital, specifically a minimum of 80% of its net assets, to equity securities. These are shares of U.S. companies with medium market capitalizations, which the portfolio's management identifies as having robust, above-average potential for earnings growth. The fund's advisor generally benchmarks these mid-cap companies, at the time of investment, against those found within the Russell Midcap® Growth Index for market capitalization comparability.