Twitter Bombs on Early Earnings Release; Merck Leads Dow, S&P 500

Stocks endured a choppy day of trading following a mixed bag of corporate earnings and as the Federal Reserve began their two-day meeting to discuss monetary policy. Twitter (TWTR) tumbled 18% in the final hour of trading after earnings were accidentally posted an hour early. The company said it is investigating the leak. The social media network earned $0.07 a share, above estimates, though sales came in light. Second-quarter revenue guidance also disappointed. Merck (MRK) was the best performer on the S&P 500 and Dow after beating on the top- and bottom-line. Whirlpool (WHR) dragged on the S&P 500 after cutting its full-year outlook.