NEW YORK ( Stockpickr) -- Professional traders don't just look at a stock's price moves; they also look for big changes in volume.

Major moves in volume can signal unusual activity, such as insider buying or selling -- or buying or selling by "superinvestors."

Let's take a look at several stocks rising on unusual volume today. In today's trading, these stocks are all already recording volume that is 87% or more above their average trading volume for a full day.

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United Therapeutics ( UTHR) is a biotechnology company focused on the development and commercialization of products to address the unmet medical needs of patients with chronic and life-threatening cardiovascular and infectious diseases and cancer. The stock is trading up 1% at $40.14 in recent trading.

Volume: 5.2 million

Average Volume: 1.6 million

Volume % Change: 220.4%

On Tuesday, United Therapeutics announced plans to offer $210 million in senior notes and to buy back up to $212 million worth of stock.

The stock is one of the top holdings of Steven Cohen's SAC Capital as of the most recently reported period.

Liz Claiborne ( LIZ) and its subsidiaries are engaged mainly in the design and marketing of a global portfolio of retail-based premium brands, including Juicy Couture and Kate Spade. The stock is trading up 32.6% at $6.76 in recent trading.

Volume: 15.1 million

Average Volume: 3.5 million

Volume % Change: 320.8%

On Wednesday, Liz Claiborne announced plans to sell several brands for $328 million -- including its namesake brand, which will go to J.C. Penney ( JCP) -- to focus on higher-end brands such as Kate Spade and Juicy Couture. The company will also change its name.

Onyx Pharmaceuticals ( ONXX) is a biopharmaceutical company is engaged in the development of innovative therapies that target the molecular mechanisms that cause cancer. The stock is trading up 6% at $33.81 in recent trading.

Volume: 2.8 million

Average Volume: 901,600

Volume % Change: 214.8%

On Wednesday, Onyx and Bayer a settlement in the lawsuit over the development and marketing of the cancer drug regorafenib in which Onyx will receive 20% royalty from Bayer on worldwide sales of the drug.

Cooper ( COO) develops, manufactures and markets health care products, primarily medical devices, through its two business units, CooperVision and CooperSurgical. The stock is trading up 1.9% at $73.54 in recent trading.

Volume: 1.6 million

Average Volume: 517,100

Volume % Change: 200.4%

TE Connectivity ( TEL) is a provider of engineered electronic components, network solutions, specialty products, and subsea communication systems. The stock is trading up 9.2% at $33.50 in recent trading.

Volume: 6.1 million

Average Volume: 2.8 million

Volume % Change: 119.2%

News broke late Tuesday that TE Connectivity will will join the S&P 500, replacing Cephalon ( CEPH), which is being acquired by Teva ( TEVA).

Gentiva Health Services ( GTIV) provides comprehensive home health services throughout most of the U.S. The stock is trading up 24.7% at $4.79 in recent trading.

Volume: 2 million

Average Volume: 778,326

Volume % Change: 160.6%

Gentiva shows up on a recent list of 5 Stocks With High Debt Burdens.

NeuStar ( NSR) provides essential clearinghouse services to the communications industry and enterprise customers. The stock is trading up 8.6% to $30.45 in recent trading.

Volume: 900,886

Average Volume: 480,705

Volume % Change: 87.4%

NeuStar, which announced it will acquire TarguSinfo for about $650 million in cash, raised full-year earnings guidance to $1.76 to $1.84 a share, from $1.68 to $1.76 a share previously.

NeuStar a holding in the portfolio of Eric Mindich's Eton Park Capital, shows up on a recent list of 7 Low-PEG, High-Momentum Stocks.

Liberty Media ( LSTZA), through its ownership of interests in subsidiaries and other companies is engaged in the video and on-line commerce, media, communications and entertainment industries. The stock is trading up 3.6% at $63.08 in recent trading.

Volume: 772,754

Average Volume: 366,000

Volume % Change: 111.1%

Liberty Media was featured recently in " 5 Netflix Screw-Ups." The end of Starz's contract with Netflix will mean Netflix will have less content come February 2012.


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