Oil prices: After a sharp jump the day before, benchmark U.S. crude slipped to $50.70 a barrel Friday, and oil-related stocks followed. Northern Oil & Gas slipped 3 percent, closing at $7.81. Its shares were up 8 percent for the week.

Bad memory: SanDisk dropped 17 percent Thursday, to $66.20 after the maker of flash memory chips cut its revenue forecast. The company said sales were weaker than expected amid falling prices. Shares closed Friday at $64.59.

Students wanted: Apollo Education Group posted a quarterly loss as enrollment fell at its for-profit University of Phoenix. Shares tumbled 29 percent Wednesday, to $19.99, closing the week at $19.19.

Ketchup and hot dogs: H.J. Heinz and Kraft Foods said they would merge to create one of the world's largest food companies. Kraft's stock shot up 35 percent, to $82.77 and closed the week at $89.10.

Spicy earnings: Spice and seasonings giant McCormick & Co. shares rose 3 percent, to $75.12 Tuesday after it reported earnings that beat Wall Street expectations. Shares closed the week at $77.33.

Lower payout: Freeport-McMoRan's shares fell 1.4 percent Tuesday, to $19.05 when the Phoenix-based mining company said it will cut its dividend by 84 percent due to falling commodity prices. Shares closed the week at $18.80.

Warning: Gilead Sciences shares dropped following news Monday that the pharmaceutical company told physicians that nine patients taking its hepatitis C treatments developed slow heartbeats and that one died. Gilead slid 2 percent, to $100.53. It closed the week at $ 101.00.