The 1987 global stock-market crash was nicknamed Black Monday.
On October 19, 1987, the Dow Jones Industrial Average fell 508.32 points, or 22.6 percent, its largest one-day percentage decline. Major markets in Europe, Asia, and elsewhere also dropped, making the episode global rather than limited to the United States.
Researchers have linked the fall to overvalued shares, rising interest rates, international trade tensions, and computerized portfolio-insurance strategies that generated additional selling. The precise balance of causes remains debated, but the speed of the decline showed how modern markets could transmit stress rapidly.
Black Monday is sometimes confused with the Black Monday of 1929, which occurred on October 28. The 1987 crash did not lead to a depression comparable to the 1930s. Regulators later introduced circuit breakers and other mechanisms intended to slow trading during extreme price movements.