Benzinga's Top #PreMarket Losers

Knowles Corporation KN shares declined 21.26% to $17.04 in pre-market trading after the company reported downbeat Q4 results and issued a weak Q1 outlook. Zynga, Inc.ZNGA shares dropped 12.41% to $2.33 in pre-market trading after the company reported downbeat fourth-quarter revenue and issued a first-quarter outlook below views. Ballard Power Systems Inc. BLDP fell 5.82% to $2.75 in pre-market trading after gaining 7.75% on Thursday. ConAgra Foods, Inc. CAG shares fell 1.76% to $35.78 in pre-market trading after the company lowered its 2015 earnings forecast and named Sean Connolly as its new CEO. Groupon, Inc.GRPN shares dropped 1.74% to $7.33 in pre-market after the company reported better-than-expected fourth quarter results, but issued a weak outlook for the first quarter.