The 28 October 1929 Wall Street trading day was known as Black Monday. The Dow Jones Industrial Average fell 38.33 points, or nearly 13%, as panic selling intensified during the Wall Street Crash.
Black Monday followed Black Thursday, 24 October, when heavy selling first shook confidence, and it preceded Black Tuesday, 29 October, when the Dow fell nearly 12%. Together, these sessions became the most famous phase of the 1929 market collapse. The market had previously risen rapidly during the 1920s, supported by speculation and widespread purchases made with borrowed money.
The crash itself did not single-handedly cause the Great Depression, but it contributed to a broader collapse in investment, employment, production, and banking. Falling share prices damaged confidence and reduced wealth, while financial failures and policy choices deepened the downturn.
A common mix-up is to use “Black Tuesday” for the entire crash. In historical usage, Black Monday and Black Tuesday refer to separate trading days. The 1929 crash is also distinct from the 1987 Black Monday, which involved a different market and economic setting.