What term describes the sudden global stock-market plunge on October 19, 1987?

The sudden global stock-market plunge on October 19, 1987, is known as Black Monday.

The event was global rather than purely American. Hong Kong fell first, European markets followed, and the Dow Jones Industrial Average then dropped 508 points, or 22.6%, in one session. Australia and New Zealand also experienced major losses as the shock moved across time zones.

Researchers have identified several contributing factors rather than one universally accepted trigger. These included rising interest rates, a widening U.S. trade deficit, investor concern about overvaluation, and computerized trading systems that generated more sell orders as prices declined.

The name can cause confusion because “Black Monday” has also been used for other market declines. In stock-market history, the 1987 reference is usually identified by its date, October 19. The episode led regulators to develop circuit breakers and other mechanisms intended to slow panic selling.