The S&P 500 index has logged an annualized return of 10.46% since...

The S&P 500 index has logged an annualized return of 10.46% since 1926, according to a report from Standard & Poor's. Almost half of that return - 41.28% - came from dividends. In 2004, the average price-to-earnings ratio for the S&P 500 companies was estimated to be 20.67, compared with an average of 15.63 since 1935, and 28.48 since 1996.