What was the name of the 1987 market crash’s famous trading day on October 19?

The famous October 19, 1987 trading day was called Black Monday.

Markets plunged around the world on that Monday, with the Dow Jones Industrial Average losing 22.6% in the United States. The decline was the largest one-day percentage fall in the Dow’s history, and similar collapses occurred in markets including Hong Kong, Australia, the United Kingdom, and Canada.

The crash followed a period of rising share prices and concern about interest rates, exchange rates, trade imbalances, and economic growth. Automated trading and portfolio-insurance programs added selling pressure as prices declined. Because trading technology and market links had changed rapidly, the event challenged existing ideas about how markets behaved under stress.

“Black Monday” can refer to other financial shocks, so the date is important. October 19, 1987 is the standard reference for the global stock-market crash. It should not be confused with Black Monday in 1929, which refers to October 28, or with later market declines that reused the label.