Which one of the following statements is correct? The S&P 500 Index is based on 500 large companies that trade on U.S. exchanges. Because of mergers and bankruptcies, the S&P 500 Index no longer contains 500 stocks. The S&P 500 Index is carefully constructed to reflect the values of large, medium and small capitalization companies. The S&P 500 is based on the 500 small U.S. companies as measured by market value