The Dow Jones Industrial Average closed at 1,738.74 on Black Monday, October 19, 1987.
That closing value followed the largest one-day percentage decline in the Dow’s history: a 22.6% fall from the previous trading session. The index had closed at 2,246.74 on October 16, so the crash erased more than 500 points in a single day. The point loss was unprecedented at the time, although later market levels made percentage comparisons more important than raw points.
Black Monday was part of a worldwide market sell-off. Shares also dropped sharply in Hong Kong, London, Australia, and other financial centers as investors reacted to concerns about overvalued markets, rising interest rates, trade tensions, and computerized trading strategies.
The crash did not develop into a depression like the 1930s collapse. Central banks supplied liquidity, and the Federal Reserve said it was ready to serve as a source of support for the financial system. The market’s closing level is sometimes confused with its opening level or with the Dow’s percentage loss.