The Rydex Russell Top 50 ETF (Ticker: XLG) seeks investment results that correspond generally to the performance, before fees and expenses, of the Rydex Top 50 Index. The index measures the market capitalization weighted performance of the 50 largest companies in the Russell 3000 Index. Russell ranks each common U.S. stock from the largest to the smallest market capitalization. The top 3,000 stocks become the Russell 3,000 Index. The top 50 of the Russell 3000 become the Russell Top 50 Index. The index is rebalanced annually every June.