The Dow Jones Industrial Average fell 22.6% on October 19, 1987, during the global stock-market crash known as Black Monday.
The one-day percentage loss remains the largest in the Dow’s history. Selling began in markets in Asia and Europe before spreading to Wall Street, where fear, computerized trading, portfolio insurance, and rising interest rates intensified the decline.
The crash was not the same event as the Wall Street Crash of 1929. In 1987, the Dow recovered much of its loss relatively quickly, and the episode did not produce the prolonged economic depression associated with the 1930s. Regulators later introduced circuit breakers to pause trading during exceptionally sharp falls.
The date is sometimes confused with October 19 in other years, but “Black Monday” in stock-market history most specifically refers to October 19, 1987.