Take a look at some of Monday's midday movers:
Apple – Shares of the technology company rose after Carl Icahn dropped his demand for Apple to repurchase more of its shares.
Darden Restaurants – Shares gained after Starboard Value, which holds a 5.5 percent stake in the company, said in a letter that it opposed the company spinning off its Red Lobster unit and called for changes to its board.
Bristol-Myers Squibb – The biopharmaceutical company gained after BMO Capital upgraded it to outperform from market perform.
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.
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—By CNBC's Rich Fisherman.
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