Black Tuesday was the 1929 Wall Street trading day when the Dow Jones Industrial Average fell nearly 12%.
It occurred on October 29, 1929, after heavy selling had already struck the New York Stock Exchange on October 24, known as Black Thursday, and October 28, known as Black Monday. The Dow lost about 30 points, or nearly 12%, on Black Tuesday, with roughly 16 million shares changing hands.
The crash followed a speculative boom in U.S. shares during the 1920s. Many investors bought stocks with borrowed money, so falling prices forced further selling as brokers demanded additional collateral. The crash did not by itself create the entire Great Depression, but it severely damaged confidence and reduced wealth.
A common mix-up is treating Black Tuesday as the only crash day. It was the most famous day in a broader collapse that continued into 1932, when the Dow reached its low for the period.