Benzinga's Top #PreMarket Gainers

Pepco Holdings (NYSE: POM) shares jumped 18.47% to $27.00 in pre-market trading after Exelon (NYSE: EXC) announced its plans to buy Pepco for $6.83 billion.Nova Measuring Instruments (NASDAQ: NVMI) shares gained 7.07% to $10.45 in pre-market trading after the company reported better-than-expected Q1 results.RF Micro Devices (NASDAQ: RFMD) 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 (NASDAQ: SGYP) 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.