Which 1929 crash date saw the Dow Jones Industrial Average fall 12.8%?

The Dow Jones Industrial Average fell 12.8% on October 28, 1929, during the Wall Street crash.

The session became known as Black Monday. It followed Black Thursday, when heavy selling had already shaken the market, and came one trading day before Black Tuesday. The consecutive declines showed that the market’s weakness was not a brief interruption but a broad loss of confidence.

Margin trading intensified the damage. Investors who had borrowed money to buy shares faced demands for additional cash as prices dropped. Selling to meet those demands added further pressure to already falling prices.

Black Monday is sometimes confused with Black Tuesday, the following day’s even more famous collapse. The two sessions were separate, and the Dow’s percentage loss on October 28 was smaller than its 13.5% decline on October 29. Together, they formed the sharpest phase of the October 1929 breakdown.