Which U.S. stock-market crash began on October 19, 1987, the day later called Black Monday?

The 1987 stock market crash began on October 19, 1987, the day later called Black Monday.

On that date, the Dow Jones Industrial Average fell 508 points, or 22.6%, its largest one-day percentage decline. Selling spread rapidly among international markets, making the episode a global crash rather than an isolated U.S. event.

Several factors were discussed afterward, including high valuations, rising interest rates, trade tensions, and computerized portfolio-insurance strategies that could intensify selling. No single explanation fully accounts for the speed and scale of the decline.

Black Monday is sometimes confused with the 1929 crash, whose most famous panic day was also given a weekday nickname. The 1987 episode differed in important ways: economic growth continued in many regions, and markets recovered more quickly than after 1929.