The stock-market crash that began in Hong Kong on October 19, 1987, is commonly called Black Monday.
Hong Kong’s Hang Seng Index fell 11.1% on October 19, beginning a wave of selling that moved westward through international markets. European exchanges then suffered major declines, and the New York Stock Exchange experienced its record percentage fall on the same calendar date. Because the crisis crossed time zones, the name became associated with a worldwide event rather than only a U.S. collapse.
The crash had several contributing factors, including investor concerns about economic growth, interest rates, currency values, and the large use of computerized trading strategies. A single explanation is difficult because markets were linked through news, capital flows, and synchronized investor behavior.
The phrase Black Monday had been used for other financial disasters, but 1987 made it a globally recognized term. It is distinct from Black Monday in 1929, which occurred on October 28 and preceded Black Tuesday.