Which 1987 crash is named for the weekday when global stock markets plunged?

The 1987 crash is named Black Monday because the steepest global falls occurred on Monday, October 19, 1987. The Dow Jones Industrial Average dropped 22.6 percent in one session, its largest one-day percentage decline.

The selling was international. Markets in Hong Kong, Australia, Europe, and North America fell sharply, making Black Monday an early example of how increasingly connected financial markets could transmit panic across time zones. The Dow's point decline was dramatic, but the percentage loss is the statistic most often used for comparison across eras.

Economists have proposed several contributing factors, including high valuations, trade tensions, economic uncertainty, and computerized trading strategies. The crash did not produce a depression like the 1930s collapse. Central banks and financial institutions responded with liquidity and reassurance, while market-structure reforms later addressed some trading risks.