What was the common name of the global stock-market crash on October 19, 1987?

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

The Dow Jones Industrial Average fell 508 points, or 22.6%, on that day—the largest one-day percentage decline in its history. Markets in Europe, Asia, Australia, and elsewhere also suffered severe losses, making the event international rather than solely American.

Several factors contributed, including overvalued shares, rising interest rates, worries about the U.S. trade deficit, and the rapid growth of computerized program trading. The exact cause remains debated, but automatic selling amplified the decline.

Black Monday is often confused with Black Thursday, the October 24, 1929, panic associated with the Wall Street Crash of 1929. After 1987, regulators introduced or strengthened safeguards such as circuit breakers to pause trading during extreme price movements.