Benzinga's Top #PreMarket Gainers

Halozyme Therapeutics

shares climbed 12.63% to $8.47 in the pre-market trading session after the company reported a Q1 loss of $0.22 per share and reported that the Data Monitoring Committee now supported enrollment in its PEGPH20 study. Rackspace Hosting

soared 11.81% to $30.78 in the pre-market trading after the company reported better-than-expected first-quarter earnings. Rackspace reported its quarterly earnings of $0.18 per share on revenue of $421 million. Keurig Green Mountain

shares jumped 6.04% to $117.40 in pre-market trading as Coca Cola

raised its stake in the company to 16%. McKesson

shares gained 3.25% to $179.90 in pre-market trading after the company reported upbeat fiscal fourth-quarter results. McKesson posted its adjusted earnings of $2.55 a share, beating analysts' estimates of $2.39 per share.