What are some good sources of historical stock market data for the S&P 500?

Historical data on the price performance of the S&P 500 stock market index over the past 10 years is available from S&P Dow Jones Indices and other financial sites, such as Morningstar. S&P Dow Jones Indices also has links to analytical reports based on historical performance.

On average, the annual return of the S&P 500 from 1928 to 2014 was 10 percent, although adjustment for inflation drops that average return to 7 percent, Investopedia reports. Because approximately 40 percent of S&P returns are paid in dividends, an investor who reinvested his dividend earnings would see a historical return of far more than the annual average, notes Investopedia.