The 1987 global stock-market crash was nicknamed Black Monday, and the Dow fell 22.6 percent in that U.S. trading session.
On October 19, 1987, stock markets around the world fell sharply. The Dow Jones Industrial Average dropped 508 points, or 22.6 percent, its largest one-day percentage decline. Markets in Hong Kong, Australia, the United Kingdom, and other countries also suffered major losses.
Several explanations have been studied, including high valuations, investor anxiety, international trade tensions, portfolio insurance, and computerized trading. No single cause fully explains the worldwide speed and scale of the collapse. Regulators subsequently introduced circuit breakers and other measures intended to slow panic-driven trading.
Black Monday is sometimes confused with Black Tuesday, the major 1929 crash day, or with the 1987 crash’s other market dates. In U.S. usage, Black Monday specifically refers to October 19, 1987.