There was no fuse mechanism in the American stock market at first. Until 1987, the Dow Jones index plummeted by 22.6%, and many people lost their money in one day. At this point, starting from 1988, the US Commodity Futures Trading Commission and the US Securities and Futures Commission approved the fuse mechanisms of the new york Stock Exchange and the Chicago Mercantile Exchange. Before 20 12, the benchmark index of the fuse mechanism in the United States was the Dow Jones industrial average, which was later changed to the Standard & Poor's 500.