Which crash saw the Dow Jones Industrial Average lose 22.6% on 19 October 1987?

Black Monday was the 19 October 1987 crash in which the Dow Jones Industrial Average lost 22.6%.

The fall was the largest one-day percentage decline in the Dow’s history. Selling spread internationally, affecting stock exchanges in Hong Kong, Australia, the United Kingdom, Canada, and other markets. The decline was especially striking because it happened after a long bull market and did not immediately produce a depression comparable to the 1930s.

Several explanations were debated, including computerized program trading, portfolio insurance, overvalued shares, trade tensions, and market structure. No single cause completely explains the event. Regulators later introduced coordinated market-wide trading halts, commonly called circuit breakers, to pause trading during extreme moves.

Black Monday is sometimes confused with the 1929 crash dates, which included Black Thursday and Black Tuesday. It is also distinct from Black Monday episodes in other countries and years. The 1987 event refers specifically to 19 October 1987.