We calculated the one-year return, trailing three-year return, and trailing five-year return (price only) between 1970 and 2012. During this 43-year period, the average number of stocks in the S&P 500 index that doubled in any one year averaged 1.8 percent, or about nine stocks out of 500. Over three-year rolling periods, 15.3 percent of stocks doubled, about 77 stocks out of 500. In rolling five-year blocks, 29.9 percent doubled, about 150 out of 500.
