(Read More: See the Day's Top Percentage Winners & Losers)
Groupon - The daily deals company's stock has been upgraded to "buy" from "neutral" at Stern Agee.
Cliffs Natural Resources - Cliffs earned $0.62 per share, excluding certain items, for the fourth quarter, nine cents above estimates. But the iron ore and coal producer also slashed its dividend by 76 percent, as a sharp drop in iron ore prices impacts its business.
Buffalo Wild Wings - The company reported fourth-quarter profit of $0.89 per share, seven cents below estimates, though revenue came in above consensus. The restaurant chain did see upbeat sales trends, but analysts are concerned over high prices for chicken wings, which has forced the company to raise menu prices.
Rackspace - Rackspace reported fourth-quarter profit of $0.21 per share, matching estimates, but its revenue came in below consensus. The numbers are accelerating concern about slowing growth for the web hosting company and its competitors.
Netgear - Netgear earned $0.55 per share for the fourth quarter, one cent above estimates, with revenue also beating consensus. However, the network equipment maker forecast current-quarter revenue below what the Street is expecting, because of a cut in spending from Internet service providers.
Moody's - The rating agency has increased its stock buyback program by $1 billion dollars, in addition to the $677 million remaining from a prior authorization.
WellPoint Health - The health insurer has named Joseph Swedish as its new chief executive officer. Swedish had been chief executive of not-for-profit hospital group Trinity Health.
J.C. Penney - The retailer has boosted its borrowing capacity by $100 million to $1.85 billion, as well as expanding an option to borrow more in the future. The move is causing concern among some analysts about the company's turnaround plan.
Legg Mason - The investment firm has named interim chief executive Joseph Sullivan as its permanent CEO.