The 29 October 1929 U.S. market collapse was called Black Tuesday.
Black Tuesday saw roughly 16 million shares traded on the New York Stock Exchange, a record at the time. The Dow Jones Industrial Average lost about 12%, extending the panic that had begun days earlier. It became the most famous single date associated with the Wall Street Crash of 1929.
The crash did not instantly create every condition of the Great Depression, but it severely damaged confidence and wealth. Banks, businesses, and households were affected as falling share prices intensified financial stress. Black Thursday, Black Monday, and Black Tuesday are related dates within the same 1929 market breakdown, not separate unrelated crashes.