[] Monday 28 October 1929, when prices on the New York Stock Exchange fell to a very low level; Monday 19 October 1987, when there was a sudden large decrease in the prices of shares (a crash) on the New York Stock Exchange. Both caused similar falls in other markets around the world.黑色星期一（1929 年 10 月 28 日星期一纽约股票交易所的股价大跌及 1987 年 10 月 19 日星期一纽约股票交易所股价暴跌。这两次都引起世界其他股票市场价格大跌）