What was the 19 October 1987 worldwide stock-market crash commonly called?

The worldwide stock-market crash on 19 October 1987 was called Black Monday.

On that day, the Dow Jones Industrial Average fell 508 points, or 22.6%, its largest one-day percentage decline. Major markets in Europe, Asia, and elsewhere also suffered steep losses, making the event global rather than solely American.

Several factors contributed, including very high share valuations, rising interest rates, investor concern about the U.S. trade deficit, and widespread use of computerized trading and portfolio insurance. These mechanisms encouraged selling as prices declined, intensifying the fall.

Black Monday is often confused with the 1929 Wall Street Crash, which began on Black Thursday and continued through several severe trading days. Unlike 1929, the 1987 crash did not lead to a comparable prolonged economic depression, and markets eventually recovered. In response, regulators introduced circuit breakers to pause trading during extreme price movements.