The 1987 global stock-market crash in which the Dow Jones Industrial Average fell 22.6% on October 19 was Black Monday.
The decline was the largest one-day percentage fall in the Dow’s history. Selling began in Asian markets, moved through Europe, and reached the United States, making the event an unusually synchronized international shock. The Dow lost 508 points that day.
Several factors were blamed, including rising interest rates, worries about the U.S. trade deficit, market overvaluation, and computerized portfolio-insurance strategies. Those automated trading systems could intensify selling once prices began to fall.
The crash is often confused with the 1929 Wall Street collapse, but the two events occurred in different economic eras. The 1987 episode also differed from 1929 because the broader financial system recovered without a prolonged depression. Regulators later introduced circuit breakers and other safeguards intended to slow trading during extreme market movements.