What nickname identifies the worldwide stock-market plunge on October 19, 1987?

The worldwide stock-market plunge on October 19, 1987, is known as Black Monday.

The Dow Jones Industrial Average fell 508 points, or 22.6 percent, in a single session. That percentage loss remains the largest one-day percentage decline in the Dow’s history. Markets in other countries also dropped sharply, making the event international rather than solely American.

Analysts have connected the crash with overvalued markets, rising interest rates, trade tensions, and computerized trading strategies such as portfolio insurance. No single explanation accounts for every market’s movement, and the exact interaction of these factors remains debated.

Black Monday is often confused with the 1929 crash’s Black Tuesday. The two events were separated by 58 years, and the 1987 decline was followed by a relatively quick recovery compared with the prolonged collapse after 1929.