The record-breaking selling of October 24 during the Wall Street Crash of 1929 occurred on Thursday, later known as Black Thursday.
The 1929 crash developed after years of rising share prices and widespread speculation in the United States. On October 24, investors rushed to sell shares on the New York Stock Exchange, producing enormous trading volume and sharp price declines. A group of major bankers temporarily supported selected stocks, but the intervention did not end the broader crisis.
Black Thursday was followed by Black Monday on October 28 and Black Tuesday on October 29. The latter two sessions brought further dramatic losses and are often treated as the crash's most famous days. The crash did not by itself cause every feature of the Great Depression, but it badly damaged confidence and helped intensify the economic downturn.
A common mix-up is to identify October 29, rather than October 24, as Black Thursday. October 29 was Black Tuesday; October 24 was the earlier Thursday panic.