In the 1987 global stock-market crash, the nickname identifying the worst trading day was Black Monday.
Black Monday occurred on October 19, 1987. The Dow Jones Industrial Average fell 22.6 percent in a single session, the largest one-day percentage decline in its history. Major markets in Europe, Asia, and elsewhere also suffered severe losses around the same time.
The crash followed a long rise in share prices and growing concerns about interest rates, trade deficits, currency movements, and market valuation. Computerized trading and portfolio-insurance strategies were also widely examined as factors that may have accelerated selling.
Unlike the 1929 crash, Black Monday did not lead to a comparable worldwide depression. Central banks supplied liquidity, exchanges introduced circuit breakers, and markets eventually recovered. The nickname can be confusing because “Black Monday” has also been used for other market declines, but the 1987 event is the famous global crash associated with it.