Benzinga's Top #PreMarket Losers By: Benzinga via Benzinga December 29, 2014 at 08:12 AM EST Ambarella, Inc. (NASDAQ: AMBA) shares dropped 3.45% to $54.01 after Needham downgraded the stock from Hold to Underperform. ... Read More >> Related Stocks: Ambarella Inc Gopro Inc Cl A Skyworks Solutions