The worst-selling session of the 1929 Wall Street Crash, October 29, was called Black Tuesday.
Trading volume reached roughly 16.4 million shares, a record at the time, as investors rushed to sell. The Dow Jones Industrial Average lost about 12%, following a fall of almost 13% on Black Monday, October 28. Together, those sessions destroyed much of the market’s value built during the 1920s boom.
Black Tuesday did not mark the end of all market declines. The Dow continued falling over the following months and reached its eventual low in July 1932, when it was roughly 89% below its September 1929 peak.
A common mix-up is treating Black Tuesday as the entire 1929 crash. The crash was a sequence of turbulent sessions, and Black Thursday, October 24, was the earlier day when unusually heavy selling first drew national attention.