The severe one-day fall in U.S. stocks on October 19, 1987, was nicknamed Black Monday.
The Dow Jones Industrial Average plunged 508 points, or 22.6%, in its largest one-day percentage decline. Selling spread rapidly across international markets, making the event a global stock-market crash rather than an isolated U.S. disturbance.
Several factors contributed, including concerns about trade deficits and interest rates, investor anxiety, and the growing use of computerized trading strategies. Portfolio insurance programs could generate additional sell orders as prices dropped, intensifying the downward movement.
Black Monday is often compared with the 1929 crash, but the economic aftermath was different. The United States did not enter a depression after 1987, and the Dow recovered much of its loss relatively quickly. In response, regulators introduced circuit breakers and other safeguards intended to pause trading during extreme declines.