The 1987 stock-market crash that began in Hong Kong and spread westward became known as Black Monday.
The crash unfolded across October 19, 1987, as severe selling moved through markets in Asia, Europe, and North America. Hong Kong experienced a major fall first, followed by other markets as trading hours advanced westward. By the time Wall Street closed, the Dow Jones Industrial Average had lost 22.6%.
The name “Black Monday” refers to the date and the dramatic market decline, not to a recurring holiday or a single company’s failure. The episode is distinct from Black Monday in 1929, a term sometimes used for October 28 of that year, and from other “Black” market days.
Explanations for the 1987 crash include stretched valuations, macroeconomic worries, market structure, and computerized selling strategies. Its international spread showed how closely linked major exchanges had become. The event also influenced later policies designed to slow panic-driven trading.