Benzinga's Top Pre-Market Gainers

Infinity Pharmaceuticals INFI soared 5.85% to $17.37 in the pre-market trading. Infinity shares have jumped 38.60% over the past 52 weeks, while the S&P 500 index has gained 27.61% in the same period. Grifols SA GRFS moved up 5.13% to $28.10 in the pre-market session. Grifols' trailing-twelve-month operating margin is 25.54%. General Motors Co GM surged 2.70% to $35.35 in the pre-market session. GM will replace H. J. Heinz Co HNZ in the S&P 500 on Thursday. Heidrick & Struggles International HSII added 2.38% to $17.66 in the pre-market session after the company confirmed that it has been approached on a preliminary basis regarding a possible sale of the Company.