Black Tuesday, the final major trading-day collapse of the 1929 Wall Street crash, occurred on October 29, 1929.
About 16 million shares changed hands on the New York Stock Exchange, a record at the time. The Dow Jones Industrial Average lost nearly 12%, following the sharp declines associated with Black Thursday and Black Monday. Panic selling overwhelmed buyers as investors rushed to exit positions.
Black Tuesday did not by itself cause the entire Great Depression. The crash exposed financial weaknesses, including widespread margin buying and speculative excess, while the later economic contraction also involved bank failures, falling production, reduced demand, and policy mistakes.
The market continued falling after October 29. The Dow eventually reached its low in July 1932, when it was roughly 89% below its September 1929 peak. The labels Black Thursday, Black Monday, and Black Tuesday refer to specific days within the broader crash.