What was the exact date of the stock market crash known as Black Monday in 1987?

The 1987 stock market crash known as Black Monday occurred on October 19, 1987.

That Monday, the Dow Jones Industrial Average fell 508 points, or 22.6%, its largest one-day percentage decline at the time. The crash was global: Asian and European markets suffered major losses before U.S. trading, and other markets continued falling afterward. In some time zones, the event is called Black Tuesday because of the local calendar date.

The collapse followed a powerful five-year bull market and growing concerns about overvalued shares, trade and budget deficits, interest rates, and automated portfolio-insurance strategies. Heavy sell orders overwhelmed market systems and worsened the lack of liquidity.

Black Monday led U.S. regulators and exchanges to develop circuit breakers and other trading curbs. These mechanisms were intended to pause trading during extreme market moves, giving investors and market professionals time to absorb information rather than reacting in an uncontrolled rush.