The FTSE 100 fell 26.45% on Black Monday in October 1987.
The London market’s FTSE 100 plunged 26.45% on October 20, 1987, one day after the Dow Jones Industrial Average suffered its record percentage fall. Because time zones spread the shock across markets, the British index experienced its largest one-day percentage decline after the U.S. session had already become synonymous with Black Monday.
The crash was not confined to the United States or Britain. Equity markets in Hong Kong, Australia, Canada, and other countries also dropped sharply. Concerns about overvalued shares, interest rates, exchange-rate tensions, and automated portfolio strategies all contributed to the international sell-off.
The FTSE 100 was launched in 1984, so the 1987 crash occurred early in the index’s history. Its loss is sometimes confused with the Dow’s 22.6% decline because both are headline figures from the same global event.