St Jude Medical - The medical device maker rose after Stifel Nicolaus raised its rating on the company to buy from hold.
The Medicines Company - Shares fell after an initial review by the U.S. Food and Drug Administration found the company's intravenous blood clot preventer should not be approved.
Sprint - The telecommunications company declined as the company was apparently reconsidering its attempt to acquire T-Mobile US.
Supertex - Shares of the maker of integrated circuits surged after Microchip Technology said it would buy Supertex for $394 million in cash.
Changyou.com - The developer of online games fell after Morgan Stanley downgraded its shares to sell.
Dick's Sporting Goods - Shares of the retailer rose after it raised its fourth-quarter profit estimates.
ACI Worldwide - Shares of the technology company fell after its preliminary 2013 results missed expectations.
Palo Alto Networks - Shares of the information security company climbed after Globes, an Israeli business publication, reported the company was in talks to acquire the Israeli start-up Cyvera.
FireEye - The cyber security company rose after Wells Fargo began coverage with an outperform rating.
CNA Financial - The insurer gained after it said it would sell its life and group insurance business to a subsidiary of Wilton Re Holdings for about $615 million.
Loews - Shares fell after the insurance company reported its net loss widened to $198 million in the fourth quarter.
Boardwalk Pipeline Partners - The transporter of natural gas declined to a 52-week low after it reported disappointing quarterly results and slashed quarterly payments to investors 81 percent.
(Read More: See CNBC's Market Insider Blog)
—By CNBC's Rich Fisherman.
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