During the 1987 global stock-market crash, which U.S. index fell 22.6% on October 19?

During the 1987 global stock-market crash, the Dow Jones Industrial Average fell 22.6% on October 19.

That one-day decline, known as Black Monday, remains the largest single-day percentage loss in the Dow's history. The fall followed sharp declines in markets in Asia and Europe, making the event an international crash rather than an isolated American sell-off.

Program trading, portfolio insurance, overvalued shares, rising interest rates, and investor fear all contributed to the selling. The Dow lost 508 points, a number that was enormous for the market at the time, although point losses cannot be compared directly across decades because the index level changes.

The 1987 crash is often confused with the 1929 Wall Street Crash, but the two events occurred nearly six decades apart. After 1987, regulators introduced or strengthened circuit breakers designed to pause trading during extreme market moves.