Black Tuesday, the 1929 crash's largest one-day percentage loss in the U.S. stock market, occurred on October 29, 1929.
The Dow Jones Industrial Average fell 11.7% that day, after dropping 13.5% on Black Monday, October 28. Heavy selling continued after the earlier panic of Black Thursday, October 24, when the market lost about 9%.
The crash followed a speculative boom in U.S. shares during the 1920s. Many investors bought stocks with borrowed money, leaving them vulnerable when prices turned downward. The market's decline damaged confidence, investment, and employment, although the Great Depression had multiple causes beyond the crash itself.
Black Tuesday is often treated as the symbolic climax of the Wall Street Crash of 1929. It was not the only severe session: the Dow continued falling until 1932, when it reached a low roughly 89% below its 1929 peak.