The Dow Jones Industrial Average lost about 89% from its September 1929 peak to its July 1932 low during the Wall Street Crash and ensuing bear market.
The Dow reached 381.17 on September 3, 1929, before a prolonged collapse in share prices. It eventually bottomed at 41.22 on July 8, 1932. The decline between those two figures was approximately 89%, making it one of the most severe stock-market falls in modern financial history.
The crash did not by itself cause every feature of the Great Depression. Bank failures, reduced lending, falling demand, industrial contraction, monetary policy, and international debt problems also mattered. The frequently cited 24 October and 29 October 1929 sessions marked dramatic stages of the downturn, but the bear market continued for years.
The Dow recovered its pre-crash closing high only in November 1954, more than two decades after the 1932 low. This long recovery period is why the crash remains a standard benchmark for extreme market losses.