The 1987 global stock-market crash, whose worst trading day was October 19, was called Black Monday.
On October 19, 1987, the Dow Jones Industrial Average fell 508.32 points, or 22.6 percent, in a single session. That percentage drop remains the largest one-day percentage decline in the Dow’s history. Markets in other countries also suffered severe losses as selling spread around the world.
The crash followed a long rise in share prices and was intensified by computerized trading strategies, portfolio insurance, investor fear, and international market connections. Unlike the 1929 crash, it did not lead to a Great Depression.
The date is sometimes confused with Black Monday in other financial crises, because the phrase is used for more than one market collapse. In stock-market history, “Black Monday” most commonly refers to October 19, 1987.