Benzinga's Top #PreMarket Losers

shares fell 32.53 percent to $2.51 in pre-market trading. Enphase Energy reported Q3 earnings of $0.08 per share on revenue of $102.9 million. The company also issued a weak Q4 revenue forecast.

shares declined 27.79 percent to $2.91 in pre-market trading. Groupon reported better-than-expected earnings for the third quarter, but the company's sales missed analysts' estimates. The company also issued a weak forecast for the current quarter.

fell 8.05 percent to $2.97 in pre-market trading. RBC Capital downgraded MannKind from Outperform to Underperform.

shares tumbled 7.26 percent to $5.49 in pre-market trading after the company reported Q3 results and announced the acquisition of the remaining interests in its oil and gas properties offshore Southern California.

shares dipped 6.69 percent to $36.00 in pre-market trading after surging 23.10 percent on Tuesday.