Drugmakers combine: Shares in Valeant Pharmaceuticals surged Monday after the Canadian drugmaker announced it has agreed to buy Salix Pharmaceuticals for about $10 billion in cash. Valeant rose 14.5 percent, to $198.75, and ended the week at $197.48. Shares in Salix slipped 1.3 percent, to $155.87, and ended the week at $157.20.

Much improved: Home Depot shares rose Tuesday after reporting better than expected fourth-quarter results. The company also boosted its quarterly dividend by 26 percent. The stock added 3.2 percent and ended the week at $114.75.

Good and not so good: Macy's reported better-than-expected earnings for the fourth quarter, but the retailer issued a forecast that fell short of Wall Street's expectations. The stock dipped 3.5 percent, to $61.92, ending at $63.72.

Healthy results: Cyberonics surged 14.3 percent Thursday on news the medical technology company's fiscal third-quarter earnings exceeded financial analysts' forecasts. The stock added $8.66 to $69.03. On Friday, it closed at $68.50.

Oil fallout: Several drilling companies fell Thursday as oil prices slid. Newfield Exploration fell 7.1 percent, to $33.46; Ensco slid 7.2 percent, to $24.67; Chevron lost 1.3 percent, to $107.15, while Exxon Mobil dropped 1.2 percent, to $88.50.

Penney pinched: Shares in J.C. Penney slumped 6.8 percent Friday, a day after the department store chain reported a surprise loss as expenses increased. The stock closed at $8.50.