Which date marked Black Monday, the 1987 global stock-market crash’s worst one-day loss?

Black Monday, the 1987 global stock-market crash’s worst one-day loss, occurred on October 19, 1987.

The Dow Jones Industrial Average plunged 508 points, or 22.6%, in a single session. That percentage decline remains the largest one-day percentage fall in the Dow’s history. Markets in other countries also dropped sharply, making the event genuinely international rather than limited to the United States.

Several forces contributed, including rising interest rates, trade tensions, investor anxiety, and widespread use of computerized trading strategies. The crash is often confused with the 1929 Wall Street Crash, but Black Monday refers specifically to the 1987 event. Regulators later introduced circuit breakers and other safeguards intended to slow trading during extreme market movements.