The most famous panic-selling day of the 1929 U.S. stock-market crash was Black Tuesday. It occurred on October 29, 1929, when about 16 million shares changed hands on the New York Stock Exchange, a record at the time. Prices fell sharply as investors rushed to sell.
Black Tuesday followed Black Thursday, October 24, and Black Monday, October 28. Those earlier sessions had already damaged confidence, but the October 29 collapse became the enduring symbol of the Wall Street Crash. The Dow Jones Industrial Average fell about 12 percent that day.
The crash did not by itself cause the entire Great Depression, although it exposed severe weaknesses in the economy and financial system. Bank failures, falling demand, debt, and policy mistakes deepened the downturn. Black Tuesday is sometimes incorrectly treated as the single beginning of the Depression; economic contraction had already started before the crash.