Which Hong Kong stock index fell first during the global Black Monday crash of October 1987?

The Hang Seng Index fell first during the global Black Monday crash of October 1987.

Hong Kong’s market suffered a dramatic decline on October 19, 1987, before the panic reached the United States. The Hang Seng Index fell 11.1% that day, helping make Hong Kong an important early signal of the worldwide sell-off. Trading was later suspended for several days as authorities and market participants dealt with the turmoil.

The decline then moved westward through international markets. Australia and other Asian markets were affected, followed by European exchanges and Wall Street. On October 19, the Dow Jones Industrial Average fell 22.6%, the largest one-day percentage drop in its history.

The crash is often simplified as an American event because the Dow’s fall is so famous. In reality, it was global from the beginning. The Hong Kong episode also illustrates why international time zones matter in financial crises: markets opening later can react to information and losses already visible elsewhere.