The events of September 11, 2001, have caused speculation that the U.S. stock market may crash when trading resumes. History, however, suggests that there is no uniform pattern in which bad news is followed by a stock market plunge. This report presents data on the stock market response to four episodes: Pearl Harbor, the Kennedy assassination, the October 1987 stock market crash, and the Asian financial crisis of 1997. There is, of course, no guarantee that the market will behave now or in the future as it did then.