US STOCKS-S&P 500, Dow end up after late rebound; Apple, Pfizer lift By: Reuters: Company News April 28, 2014 at 17:30 PM EDT (Updates close with jump in Agenus; adds Gogo's shares down after the bell) Read More >> Related Stocks: Agenus Inc Amazon.com Apple Baidu.com SP ADR Gogo Inc Pfizer