The most famous stock market crash in history was probably on 1929's Black Tuesday, but it turns out that it wasn't the biggest. That moment fell on October 19, 1987, when the NYSE fell 508.32 points, losing twice the market value it did on the eve of the Great Depression. The stock market crash of 1987, often referred to as Black Monday, began in Hong Kong and spread west. There were many theories as to the cause of the crash, but program trading—rapid trading by computers—took the brunt of the public blame. People thought that computers had fed the fall by selling more and more stocks as the market crashed.