Benzinga's Top Pre-Market Gainers

Merge Healthcare

moved up 6.64% to $2.57 in the pre-market session after the company reported that Michael W. Ferro, Jr. has stepped down as Chairman and a Director of the company. Avanir Pharmaceuticals

surged 6.43% to $5.30 in the pre-market session. Avanir shares have jumped 73.52% over the past 52 weeks, while the S&P 500 index has gained 17.94% in the same period. Onyx Pharmaceuticals

soared 5.59% to $123.50 in the pre-market trading after Amgen

announced its plans to will buy the company for $10.4 billion. Amgen

shares gained 5.11% to $111 in the pre-market session after the company announced its plans to will buy Onyx Pharmaceuticals

for $125 per share. Analysts at Piper Jaffray upgraded Amgen from “neutral” to “overweight.”