The Dow Jones Industrial Average lost 22.6% on Black Monday, October 19, 1987.
That decline remains the largest one-day percentage fall in the Dow’s history. The crash was part of a worldwide market sell-off: stocks also plunged in Hong Kong, London, Australia, and other financial centers. The Dow fell 508 points, a record points loss at the time.
Several factors contributed. U.S. interest-rate concerns, a rising trade deficit, investor anxiety, and computerized portfolio-insurance strategies all intensified selling. Trading systems were not designed for such a sudden flood of orders, and temporary market safeguards were introduced afterward.
Black Monday is often confused with the 1929 Wall Street Crash because both occurred in October and produced dramatic headlines. However, the 1987 event did not lead to the prolonged economic collapse associated with the Great Depression. The Dow recovered much of its loss over the following months, and financial regulators later developed circuit breakers to slow extreme market declines.