Last few weeks have been rough on Twitter and Facebook shareholders. To put it in perspective, Black Monday refers to Monday, October 19, 1987 and was the worst stock market crash of our lifetime. The Dow Jones Industrial Average was down 22.61% that day. Over the past 3 weeks, Facebook is down over 22% and Twitter is down 32%. Stock declines like this are devastating losses in value. Fortunately, over the same period the S&P 500 Index rose about 4%.