Benzinga's Top #PreMarket Gainers By: Benzinga via Benzinga May 27, 2015 at 08:11 AM EDT Opexa Therapeutics Inc (NASDAQ: OPXA) shares rose 36.55 percent to $0.526 in pre-market trading. On Tuesday, Maxim Group initiated ... Read More >> Related Stocks: Bluebird Bio Cellectis S.A. ADR Five Prime Thera Tiffany & Co