The 1987 Black Monday stock-market crash occurred on October 19, 1987, when the Dow Jones Industrial Average fell 22.6% in one session.
The decline was the largest one-day percentage fall in the Dow’s history. Stock markets around the world also dropped sharply, making the event an international crash rather than an isolated American market shock.
Researchers have linked the sell-off to high valuations, rising interest rates, uncertainty about the dollar, and automated portfolio-insurance trading. These factors amplified selling once prices began falling. The crash did not produce a Great Depression, and the U.S. economy continued to grow afterward.
Black Monday is often confused with Black Tuesday in 1929, the day associated with the most famous Wall Street crash. The two events were separated by 58 years and had different economic contexts, although both became symbols of sudden market panic.