Black Tuesday was the name of the 29 October 1929 U.S. stock-market crash day when the Dow Jones Industrial Average fell nearly 12%.
The day followed Black Monday, when the Dow had already dropped 13%. Heavy selling overwhelmed the New York Stock Exchange, and more than 16 million shares changed hands on Black Tuesday, setting a trading-volume record that lasted for decades.
The crash did not single-handedly cause the Great Depression, but it severely damaged confidence and wealth. Bank failures, declining investment, falling production, and reduced consumer spending deepened the economic contraction. A common mix-up is treating Black Tuesday as the entire crash; the market decline unfolded over several days in October 1929 and continued afterward.
The Dow eventually lost almost 90% from its September 1929 peak before reaching its low in 1932. The event remains one of the most recognizable episodes in financial history.