Benzinga's Top #PreMarket Gainers

Pepco Holdings

shares jumped 18.47% to $27.00 in pre-market trading after Exelon

announced its plans to buy Pepco for $6.83 billion. Nova Measuring Instruments

shares gained 7.07% to $10.45 in pre-market trading after the company reported better-than-expected Q1 results. RF Micro Devices

soared 6.67% to $8.63 in the pre-market trading after the company reported upbeat Q4 earnings and issued a strong Q1 outlook. Synergy Pharmaceuticals

surged 6.64% to $5.14 in the pre-market session after the company reported positive results of plecanatide Phase 2b study in patients with irritable bowel syndrome with constipation.