Benzinga's Top #PreMarket Losers

Atara Biotherapeutics Inc ATRA shares dipped 37.38 percent to $20.79 after the company reported results from its Phase 2 proof-of-concept PINTA 745 clinical trial for protein energy wasting in patients with end stage renal disease. GoPro Inc GPRO fell 5.43 percent to $18.11 in pre-market trading. Morgan Stanley downgraded the rating on GoPro from Equal-weight to Underweight, while lowering the price target from $23 to $12. Chesapeake Energy Corporation CHK shares dipped 4.10 percent to $3.98 in pre-market trading after falling 8.99 percent on Friday. E I Du Pont De Nemours And Co DD shares fell 1.63 percent to $69.29 in pre-market trading. Jefferies downgraded DuPont from Buy to Hold. Apple Inc. AAPL shares tumbled 1.48 percent to $111.50 in pre-market trading. Barclays maintained Apple with a Overweight rating and lowered the price target from $155.00 to $150.00.