The 1987 Black Monday stock-market crash reached its largest one-day Dow Jones percentage fall on October 19, 1987.
The Dow Jones Industrial Average dropped 508 points, or 22.6%, that day. It was the biggest one-day percentage decline in the index's history, exceeding the percentage losses recorded during the most dramatic sessions of 1929.
The selling spread internationally, although different markets experienced their worst declines on different dates. Analysts have linked the crash to overvalued shares, investor anxiety, program trading, portfolio insurance and trade tensions. The crash did not lead to a depression, and the Dow eventually recovered its pre-crash closing level.
“Black Monday” is sometimes confused with Black Tuesday in 1929. They were separate crashes, 58 years apart, and the 1987 event remains a key example of how computerized or rule-based trading can amplify a rapid sell-off.