The Dow Jones Industrial Average reached a pre-crash high closing value of 381.17 on September 3, 1929.
That record marked the peak of a long period of rising U.S. share prices during the 1920s. Easy credit, margin buying, strong optimism, and rapid industrial growth helped fuel the boom. Many investors purchased shares with borrowed money, increasing both potential gains and potential losses.
After the September peak, the market became increasingly unstable. Selling intensified in October, and the Dow suffered several dramatic declines. The crash was followed by a much longer economic contraction associated with the Great Depression, although historians do not treat the stock-market collapse alone as its sole cause.
The figure 381.17 is the Dow's closing high before the crash period. It should not be confused with a later intraday quotation or with the percentage losses recorded on particular October trading days.