Benzinga's Top #PreMarket Gainers

Horizon Pharma

shares climbed 7.95% to $14.25 in the pre-market trading session after the company reported upbeat Q1 earnings and issued a strong FY14 sales outlook. The Gap

shares jumped 3.98% to $40.80 in pre-market trading after the company reported a 9% surge in its April same-store sales, versus analysts' expectations for a 0.5% gain. The company also issued a strong outlook for the first quarter. Ballard Power Systems

soared 3.96% to $3.15 in the pre-market trading after gaining 1.00% on Thursday. The Interpublic Group of Companies

shares gained 3.15% to $18.00 in pre-market trading after the company and Omnicom Group

called off their proposed merger.