The 19 October 1987 global stock-market crash 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, Australia, and North America also suffered sharp losses.
Several forces contributed, including high interest rates, concerns about the U.S. trade deficit, an overvalued market, and computerized portfolio-insurance trading. Automated selling intensified the decline after prices began falling, although historians do not attribute the crash to one single cause.
Black Monday is often confused with the 1929 Wall Street crash, which also included a day called Black Tuesday. The 1987 event did not develop into a depression like the 1930s collapse. Market reforms followed, including circuit breakers designed to pause trading during extreme declines.