The global stock-market crash that began on Monday, October 19, 1987, is nicknamed Black Monday.
The event was not limited to one exchange. Major markets in Hong Kong, Australia, Britain, Canada, and the United States all suffered severe losses as selling moved across time zones. Hong Kong’s Hang Seng Index fell especially sharply, helping make the episode a worldwide financial shock.
In New York, the Dow Jones Industrial Average dropped 22.6%, while the S&P 500 also suffered a historic one-day percentage decline. The crash happened after a powerful multi-year bull market, so investors were highly exposed when confidence changed.
Black Monday does not refer only to the 1929 Wall Street collapse. The nickname has also been used for other market disasters, but in stock-market history it most specifically identifies the October 19, 1987 episode.