Black Monday, the 1987 global stock-market crash, occurred on October 19, 1987. The Dow Jones Industrial Average fell 22.6% in one session, still its largest one-day percentage decline.
The selling began in Hong Kong and spread westward through Europe before reaching the United States. Investors were worried about rising interest rates, trade tensions, a slowing economy, and overvalued shares. Computerized portfolio-insurance strategies amplified the rush to sell.
The crash was not the same event as the 1929 Wall Street Crash or the 2008 financial crisis. Although the fall was dramatic, the banking system did not collapse, and the market later recovered.
The Federal Reserve, led by Chairman Alan Greenspan, issued a statement affirming its readiness to provide liquidity. Exchanges also introduced circuit breakers after 1987 to pause trading during extreme market moves.