The S&P 500 Index closed at $1,215.29 on Sept. 23, 2005 and at $1,938.76 on Sept. 23, 2015, increasing by more than $700 in the 10-year period, according to Yahoo! Finance. The index's 10-year low price of $676.53 occurred on March 9, 2009. The 10-year annualized return for the index is 6.98 percent, while five-year returns are twice as high at 13.33 percent, notes Morningstar.Continue Reading
The S&P 500 Index is a selection of the most widely held publicly traded stocks, explains About.com. The S&P attempts to track the stock market as a whole by aggregating large cap U.S. stocks. The companies included in the index must be U.S. companies that have more than half of their total stock available to the public and have market capitalizations of $5.3 billion or greater.
The index began trading on March 4, 1957, according to S&P Dow Jones Indices LLC. As of Aug. 31, 2015, the S&P 500 actually contains 502 total companies. The index's largest holdings are in the information technology, financial and health care industries, with Apple and Microsoft holding the top two spots in the index's ranking of holdings by weight. Of the top 10 companies held in the S&P 500, only the telecommunications company AT&T and energy company Exxon Mobil are not in the top three sectors.Learn more about Investing