Black Monday, October 28, 1929, recorded the greatest percentage fall in the Dow Jones Industrial Average during the Wall Street Crash of 1929.
The Dow fell 12.82% that day, after investors had already become alarmed by heavy selling and weakening confidence. The decline was followed immediately by another severe session on Black Tuesday, October 29, when the Dow fell 11.73%. Together, the two days turned a major correction into a historic collapse in public confidence.
Black Monday is often confused with Black Tuesday because the latter became the crash’s most famous date and set a record for trading volume at the time. The names describe separate sessions. The market’s decline then continued, and the Dow eventually reached its low in July 1932, far below its 1929 peak. The crash was associated with the Great Depression, but historians identify multiple causes for the broader economic disaster, including debt, banking weakness, reduced production, and international financial pressures.