Real time data on the E-mini S&P 500 Index Futures. The S&P (abbreviation of "Standard & Poor's") 500 Index is a capitalization-weighted index of 500 stocks. The index is designed to measure performance of the broad domestic economy through changes in the aggregate market value of 500 stocks representing all major industries. It is believed to represent the U.S. economy accurately due to diversity and vast coverage of the stock market. More information can be found in other sections of this page, via the navigation tabs; real time data, historical data, charts, technical analysis and a user discussion area.