It has been 513 calendar days since the stock market peaked on Oct. 9, 2007. Since then, the S.&P. 500 is down 56 percent and the Dow is off 53 percent. On Jan. 29, 1931—the identical number of days after the 1929 market peak—the S.&P. 500 was down 49 percent and the Dow was down 56 percent. The 1929 crash got off to a much faster start, but we have now more or less caught up.