Black Monday, 1987, saw the Dow Jones Industrial Average fall 22.6%, the largest one-day percentage drop in its history.
The crash occurred on October 19, 1987, as stock markets around the world plunged. The Dow lost 508 points, a large point decline for the period, while markets in Hong Kong, Europe, Australia, and Canada also suffered severe falls.
Several factors were associated with the collapse, including overvalued shares, rising interest rates, trade tensions, and computerized portfolio-insurance strategies. Automated selling could amplify falling prices, although historians and economists continue to debate the relative importance of each cause.
Black Monday differed from 1929 because the wider economy did not enter a comparable decade-long depression. Central banks supplied liquidity, and reforms later introduced circuit breakers and other mechanisms intended to slow extreme market movements.