What nickname describes the sharp U.S. stock-market decline of October 19, 1987?

Black Monday is the nickname for the sharp U.S. stock-market decline of October 19, 1987.

On that day, the Dow Jones Industrial Average fell 508 points, or 22.6 percent, its largest one-day percentage decline. Stock markets in other countries also dropped sharply, making the event a global crash rather than an isolated Wall Street disturbance. Hong Kong’s market fell first in the sequence, followed by major markets in Europe and North America.

The causes remain debated. Investors worried about slowing economic growth, high valuations, trade tensions, and rising interest rates. Computerized portfolio-insurance programs and other automated selling mechanisms amplified the fall. Unlike the 1929 crash, Black Monday did not lead to a decade-long depression. The Federal Reserve, led by Alan Greenspan, reassured markets that it would provide liquidity, and trading systems were later revised with circuit breakers designed to pause extreme declines.