The global stock-market crash on October 19, 1987, when the Dow fell 22.6%, was called Black Monday.
The Dow Jones Industrial Average dropped 508 points that day, its largest one-day percentage decline in history. Selling spread rapidly from Hong Kong and Europe to the United States, making the event a global market shock rather than an isolated American collapse.
Several factors contributed, including computerized trading, portfolio insurance, high valuations, and concern about interest rates and the dollar. The crash was not caused by one universally accepted event, and the U.S. economy did not enter a depression afterward.
The name can be confused with other “Black Monday” events, including the 1929 market decline. In response to the 1987 crash, U.S. regulators introduced circuit breakers designed to pause trading during extreme market moves.