Stocks were walloped Friday in a second straight day of big-volume selling as China's factory orders came in weaker than expected and the Shanghai Composite fell overnight below its 200-day moving average for the first time since July 2014. More economists were calling into question whether the Federal Reserve can raise interest rates in September. The Nasdaq tanked 3.5%; the S&P 500 tumbled 3.2% and the Dow Jones industrial average dropped... More