Black Tuesday was the 1929 trading day that gave the Wall Street crash its most famous name, after the Dow Jones Industrial Average fell nearly 12 percent.
Black Tuesday occurred on October 29, 1929, when about 16 million shares changed hands on the New York Stock Exchange. The heavy selling followed major declines on Black Thursday, October 24, and Black Monday, October 28.
The crash ended the speculative boom of the 1920s and helped usher in the Great Depression, although historians do not treat the crash alone as its sole cause. Bank failures, reduced lending, falling demand, and international economic problems deepened the downturn.
Black Tuesday is sometimes used as a name for the entire 1929 crash, but technically it identifies one especially severe session. The Dow continued falling after October 29 and did not reach its low until July 1932.