What term describes the 1987 global stock-market crash?

The 1987 global stock-market crash is commonly called Black Monday.

Black Monday refers specifically to October 19, 1987, when markets around the world collapsed. The Dow Jones Industrial Average lost 508 points, equal to 22.6 percent, in one session. London, Hong Kong, Australia, Canada, and other markets also recorded severe declines around the same period.

The crash followed a powerful bull market and came amid worries about inflation, interest rates, currency arrangements, and international trade. Program trading and portfolio-insurance strategies amplified selling once prices began to fall. The event prompted reforms intended to reduce disorderly trading, including coordinated trading halts and market-wide circuit breakers. It is sometimes confused with Black Monday in 1929, but the 1987 label is tied to October 19 and is the most famous use of the term in stock-market history.