Benzinga's Top #PreMarket Gainers By: Benzinga via Benzinga December 19, 2014 at 09:01 AM EST b>Aratana Therapeutics, Inc. (NASDAQ: PETX) jumped 37.87% to $18.02 after the company announced positive top-line results from AT-001 ... Read More >> Related Stocks: Aratana Theraptcs Cerus Corp Pier 1 Imports Xerox Corp