The global stock-market crash known as Black Monday began in 1987.
On Monday, October 19, 1987, stock markets around the world fell sharply. The Dow Jones Industrial Average dropped 508 points, or 22.6%, in a single session, its largest one-day percentage decline at the time. Markets in Hong Kong, Australia, the United Kingdom, Canada, and other countries also suffered major losses.
The crash had several contributing factors rather than one universally accepted trigger. Concerns about overvalued shares, rising interest rates, trade deficits, and the U.S. dollar combined with computerized portfolio-insurance strategies and other forms of program trading. Selling accelerated as automated strategies responded to falling prices.
Black Monday is often confused with the 1929 Wall Street Crash because both involved dramatic U.S. share-price declines. The 1987 event was different: financial markets recovered relatively quickly, and the wider economy did not enter a depression comparable to the 1930s. Regulators later introduced circuit breakers to help slow extreme market moves.