The 19 October 1987 stock-market collapse was called Black Monday.
On that day, the Dow Jones Industrial Average fell 508 points, or 22.6%, its largest one-day percentage decline in history. Major markets around the world also suffered steep losses, making the event an international crash rather than an isolated American sell-off.
Analysts have linked the fall to overvalued shares, rising interest rates, anxiety about trade deficits, and computerized portfolio insurance that accelerated selling. The precise balance of causes remains debated.
Black Monday is sometimes confused with the Wall Street Crash's Black Tuesday in 1929. The 1987 crash did not produce a depression comparable to the 1930s, and the Dow recovered much of its loss within about two years.