In the 1987 stock-market crash, what was the name given to October 19, 1987?

October 19, 1987, the key day of the 1987 stock-market crash, was called Black Monday.

The Dow Jones Industrial Average fell 508 points, or 22.6%, in a single session. That percentage decline remains the largest one-day percentage drop in the Dow’s history. Markets in other countries also plunged, making the episode a global crash rather than an isolated American event.

Several factors contributed. Valuations had risen strongly, interest rates were changing, investor confidence was fragile, and computerized portfolio-insurance strategies accelerated selling. Those automated strategies were intended to limit losses, but their simultaneous use added to downward pressure in rapidly falling markets.

Black Monday did not lead to a depression like the crash of 1929. The Federal Reserve supplied liquidity, regulators reviewed market safeguards, and exchanges later introduced circuit breakers to pause trading during extreme moves. The Dow eventually recovered, although the crash permanently changed thinking about market structure and automated trading.