Which major stock-market crash began on October 19, 1987?

The major stock-market crash that began on October 19, 1987, is known as Black Monday.

On that day, the Dow Jones Industrial Average plunged 22.6 percent, its largest one-day percentage decline. Selling spread rapidly across international markets, with major indexes in London, Hong Kong, Australia, and elsewhere also suffering steep losses. The speed of the decline made the event especially shocking.

Several factors contributed, including high valuations, rising interest rates, trade and currency tensions, and the growing use of computerized portfolio insurance. Automated selling strategies could reinforce downward momentum when prices breached predetermined levels. The market structure of the period was not designed for such a sudden wave of orders.

Unlike the 1929 crash, Black Monday did not lead directly to a decade-long depression. The United States later introduced circuit breakers and other safeguards, while central banks supplied reassurance and liquidity. Black Monday is also distinct from the 1987 crash’s later international trading sessions, which extended the shock beyond New York.