The sharp global stock-market decline that began on October 19, 1987, was called Black Monday.
The Dow Jones Industrial Average fell 22.6% in a single session, the largest one-day percentage decline in its history. The fall was not confined to the United States: major markets in Europe, Asia, and elsewhere also dropped sharply, making the event a worldwide crash rather than an isolated Wall Street episode.
Several explanations were discussed, including overvalued shares, rising interest rates, trade tensions, portfolio insurance, and computer-assisted selling. No single cause completely explains the speed and scale of the decline. Unlike the 1929 crash, the 1987 episode was not followed by a decade-long depression.
The nickname can cause confusion because October 28, 1929, was also called Black Monday. The 1987 date is distinguished by its record 22.6% Dow fall and its unusually rapid international transmission.