The United Kingdom experienced the 1987 crash’s largest one-day percentage fall among the major European markets listed in standard accounts.
On October 19, 1987, the Financial Times Stock Exchange 100 Index, or FTSE 100, fell 10.8%. The decline came during a worldwide sell-off that also hit the United States, Hong Kong, Australia, and other markets. London’s market was strongly linked to international capital flows and was affected by the same broad wave of fear and forced selling.
The U.S. Dow Jones Industrial Average fell a record 22.6% that day, the largest one-day percentage decline in its history. The different percentages reflect different indexes, market structures, and trading conditions, so comparing them requires naming the benchmark precisely.
The crash led regulators and exchanges to strengthen market safeguards, including circuit breakers and coordinated procedures for extreme volatility. It did not produce the prolonged economic depression many observers initially feared.