Black Monday stock market crash

On October 19, 1987, the Dow Jones Industrial Average fell 22.6% in a single session, the worst one-day percentage drop in its history, and the sell-off spread to markets in Europe and Asia within hours. Program trading and portfolio-insurance strategies, which automatically sold stocks as prices fell, are widely blamed for amplifying the decline once it started. Unlike the crashes of 1929 or 2008, Black Monday did not trigger a lasting recession — central banks, led by the newly-appointed Fed chair Alan Greenspan, moved quickly to reassure markets with liquidity, and equities recovered most of their losses within about two years. The episode nonetheless reshaped market-circuit-breaker rules used to this day.