The British stock index that fell 26.4% on Black Monday in 1987 was the FTSE 100.
On October 19, 1987, the FTSE 100 suffered a fall of about 26.4 percent as the worldwide equity sell-off reached London. The index, launched in 1984, tracks major companies listed on the London Stock Exchange and is one of the United Kingdom's best-known market indicators.
The same day brought a 22.6 percent fall in the Dow Jones Industrial Average in New York. Markets in Hong Kong, Australia, and other financial centers also recorded severe losses. The synchronized declines showed how increasingly connected international markets had become.
The FTSE 100 is sometimes confused with the DAX, Germany's leading share index, or the CAC 40, France's benchmark. Those indexes also fell during the 1987 crash, but the 26.4 percent British figure belongs specifically to the FTSE 100. Trading systems and market safeguards were later reviewed internationally.