The top after-market NASDAQ Stock Market gainers are: Expedia, Seagate Technology, Cutera, ShoreTel, and Select Comfort. The top after-market NASDAQ Stock Market losers are: Hercules Offshore, Idenix Pharmaceuticals, Sangamo Biosciences, PostRock Energy, and China-Biotics.

Gainers

Expedia Inc. (EXPE) stock jumped 13.88 percent to $25.51 in the after-market trading, as its board of directors has preliminarily approved a plan to separate the company into two publicly traded entities -- Expedia Inc. and TripAdvisor. The proposed spin-off is expected to be completed in the third quarter of 2011.

Expedia Inc. will continue to include the domestic and international operations of the company's travel transaction brands including Expedia.com, Hotels.com, eLong, Hotwire and others. On other hand, TripAdvisor will include the domestic and international operations associated with the TripAdvisor Media Group, which includes its flagship brand as well as 18 other travel media and advertising brands.

The company expects to effect the spin-off through a distribution of TripAdvisor shares to Expedia shareholders or a reclassification of Expedia stock. In either case, the transaction is expected to be tax free. The transaction is subject to a number of conditions including final approval by Expedia's board of transaction specifics. In addition, it is expected that Expedia will seek stockholder approval of the transaction.

Seagate Technology PLC (STX) stock grew 7.69 percent to $15.82 in the after-market trading, as it guided third quarter revenue above Street view. The company expects third quarter revenue of about $2.7 billion, while Street predicts $2.62 billion. Seagate expects third-quarter shipments of 49 million units and anticipates gross margin near or slightly above the high-end of the original outlook of 18 percent to 19 percent. Seagate said its board has approved a quarterly cash dividend of 18 cents a share, payable on June 1 to shareholders of record on May 2.

Cutera, Inc. (CUTR) stock gained 5.93 percent to $9.11 in the after-market trading, as the U.S. Food and Drug Administration (FDA) approved its GenesisPlus laser device for treatment of onychomycosis. Known medically as onychomycosis, nail fungus often causes the toenails to become discolored, thickened and separated from the nail bed. About half of the population will have at least one infected toenail during the course of their lives. Current treatment options include prescription topicals and oral drugs, both with limited success rates. Some patients are not candidates for oral medications, due to concerns of liver damage and other treatment limitations.

GenesisPlus utilizes Cutera's patented microsecond technology and features a proprietary delivery system with a temperature sensor to improve the practitioner and patient experience. The GenesisPlus laser is a great innovation in the treatment of fungal nails and it has exceeded my expectations for safety and efficacy, said David Weiss, Doctor of Podiatric Medicine in private practice in Hammonton, New Jersey.

ShoreTel, Inc. (SHOR) stock increased 4.99 percent to $9.67 in the after-market trading.

Select Comfort Corp. (SCSS) stock rose 4.53 percent to $12.91 in the after-market trading.

Losers

Hercules Offshore, Inc. (HERO) stock plunged 12.38 percent to $5.59 in the after-market trading. In a regulatory filing, the company said it has received a subpoena issued by the Securities and Exchange Commission (SEC) requesting the delivery of certain documents to the SEC in connection with its investigation into possible violations of the securities laws, including possible violations of the Foreign Corrupt Practices Act in certain international jurisdictions where the company conducts operations.

The company has also notified by the Department of Justice (DOJ) that certain of its activities are under review by the Department. The company said it is currently not possible to predict the outcome of the investigations, the expenses it will incur associated with those matters, or the impact on the price of its common stock or other securities if the SEC or DOJ takes any actions regarding the investigations. The company said it plans to respond fully to the SEC subpoena and cooperate with the SEC and DOJ in their investigations.

Investor-rights law firm Hagens Berman LLP said it investigates Hercules Offshore to determine if the company violated securities laws after the announcement of a SEC investigation of certain of the company’s activities.

Idenix Pharmaceuticals Inc. (IDIX) stock plummeted 12.04 percent to $2.85 in the after-market trading. The company said it has commenced an underwritten registered public offering of shares of its common stock. All of these shares are being sold by Idenix. J.P. Morgan Securities LLC is acting as sole book-running manager and underwriter for the offering. Idenix intends to grant the underwriter a 30-day option to purchase up to an additional 15 percent of the amount sold to cover over-allotments, if any.

Sangamo Biosciences Inc. (SGMO) stock fell 7.27 percent to $7.75 in the after-market trading. The company said it is offering to sell 6.7 million common shares pursuant to an effective shelf registration statement in an underwritten public offering. Barclays Capital Inc. is the sole book-running manager in this offering and Sangamo will grant the underwriter a 30 day option to buy up to 1.005 million additional shares.

PostRock Energy Corp. (PSTR) stock slid 4.92 percent to $6.96 in the after-market trading.

China-Biotics, Inc. (CHBT) stock slid 4.48 percent to $7.68 in the after-market trading.