During the Wall Street Crash of 1929, the Dow Jones Industrial Average lost nearly 13% on October 28, 1929.
The day became known as Black Monday. It followed the panic-selling of Black Thursday, October 24, when the market suffered a major fall but was partly steadied by support from leading bankers. Selling intensified again the following week as investors rushed to exit positions and brokers faced pressure from margin calls.
The next day, Black Tuesday, October 29, brought another exceptionally severe decline. The crash was not caused by one isolated event: speculation, purchases made with borrowed money, weakening economic conditions, and fragile investor confidence all contributed. The Dow had reached a record high in September 1929 before beginning its collapse.
Black Monday is sometimes confused with Black Tuesday because both were pivotal days in the same crash. The broader economic depression that followed is called the Great Depression, but the crash itself and the depression were distinct historical events.