The 1987 crash that began in Hong Kong before spreading through European and U.S. markets was Black Monday.
Hong Kong’s market fell sharply on October 19, 1987, and the selling moved westward through international financial centers. European exchanges suffered heavy losses before the New York Stock Exchange opened. By the end of the day, the Dow Jones Industrial Average had fallen 22.6%, its largest one-day percentage decline.
The episode demonstrated how closely linked global markets had become. Investors reacted to shared economic news, currency concerns, portfolio strategies, and computer-assisted trading systems. Because trading hours overlap in sequence around the globe, selling pressure in one market could influence expectations in the next.
Black Monday is often used for several different crashes, so the year matters. The 1987 event is distinct from the 1929 Black Tuesday and from the 2020 pandemic sell-off. Its international spread also helped encourage reforms designed to coordinate trading interruptions during unusually severe price movements.