October 28, 1929, was nicknamed Black Monday during the Wall Street Crash. On that day, the Dow Jones Industrial Average fell 12.82%, one of the most severe declines of the 1929 collapse.
Black Monday followed Black Thursday, October 24, when heavy selling first shook confidence. The next day of extreme losses was Black Tuesday, October 29, when the Dow fell another 11.73%. Together, the dates became symbols of the crash.
This Black Monday is distinct from October 19, 1987, which is also commonly called Black Monday. The shared nickname refers to separate crashes, so the date is essential when identifying which event is meant.