Which 1987 crash day saw the FTSE 100 fall 10.8% in London?

The 1987 crash day when London’s FTSE 100 fell 10.8% was Black Monday.

Black Monday refers to 19 October 1987, when stock markets around the world suffered extraordinary losses. In London, the FTSE 100 fell 10.8%, while the Dow Jones Industrial Average later recorded a 22.6% decline. The international sequence showed how increasingly connected financial markets had become.

The London market had already experienced pressure before Wall Street opened. Investors were reacting to concerns about interest rates, currency values, economic imbalances, and the rapid use of computerized trading strategies. Trading systems and portfolio-insurance techniques may have accelerated selling, although they did not provide a complete explanation for the crash.

The same name creates a common mix-up: 28 October 1929 was also called Black Monday. Adding the year is essential. The 1987 event was followed by reforms such as coordinated trading halts, often called circuit breakers, designed to slow future disorderly declines.