Looking fit: Shares in Fitbit climbed 6.2 percent to $7.74 Tuesday after the fitness tracker company's app became the second-most downloaded in the iTunes store. The stock finished the week at $7.32.

Factory fallout: Endologix plunged 20.2 percent to $5.74 Tuesday after the drugmaker said that the FDA has ordered it to cease shipping a device used to treat abdominal aortic aneurysms because of manufacturing problems. The company said that no clinical problems have been reported. Endologix shares finished Friday at $5.72.

Poison pill: Fred's Inc. dropped 4.2 percent to $18.80 Wednesday on a published report indicating that the regional drugstore chain has adopted a "poison pill" to discourage an activist investor from interfering with the company's plan to buy 865 Rite Aid stores. The shares closed Friday at $18.56.

Short thrift: Nvidia slumped 6.6 percent Wednesday to $109.55 after short seller Citron Research said it expects the chipmaker's shares, which have tripled in value this year, to fall substantially. The stock closed Friday at $106.74.

Financial lifeline: Sears Holdings surged 5.5 percent to $8.65 Thursday after the struggling retailer said it obtained a letter of credit that the company can use to fund its operations. The stock closed Friday at $9.29.

All that glitters: Rising gold prices fueled a gold mining sector rise Thursday, sending Newmont Mining shares up 8 percent to $35.27. Another big riser: Barrick Gold Corp., which increased 7 percent to $16.39. Newmont shares closed the week at $34.07; Barrick finished at $15.98.