On what date did the 1987 global stock-market crash, known as Black Monday, begin?

Black Monday, the 1987 global stock-market crash, began on October 19, 1987.

The Dow Jones Industrial Average fell 508 points that day, a loss of 22.6 percent, then the largest one-day percentage decline in the index's history. Major markets in Europe, Asia, and North America also suffered severe losses as selling spread across time zones.

Several factors contributed, including high interest rates, concerns about the US trade deficit, overvalued shares, computerized trading, and portfolio-insurance strategies. The crash was not caused by one universally accepted event, although a sharp fall in Hong Kong helped create a wave of international anxiety.

Black Monday is sometimes confused with the 1929 Wall Street Crash, whose most famous session was Black Tuesday. The two events occurred 58 years apart. After 1987, regulators introduced or strengthened safeguards such as trading halts, commonly called circuit breakers, to slow disorderly market declines.