The top after-market NASDAQ gainers Thursday were: OraSure Technologies, GRAVITY Co, Pacific Biosciences of California, Digital River, Saba Software and Aceto Corp. The top after-market NASDAQ losers were: Xyratex Ltd, VIVUS, American Realty Capital Trust, Savient Pharmaceuticals, Research in Motion and Orexigen Therapeutics.

Gainers

OraSure Technologies, Inc. (OSUR) stock surged 5.49 percent to $12.10 in aftermarket session. Complete Genomics (GNOM) has said it has begun accepting DNA samples derived from human saliva. By providing the same high-quality results for saliva-derived DNA as for samples collected from blood and cell lines, this new offering opens Complete's whole human genome sequencing service to researchers who have collected or will collect saliva samples. The company is working with DNA Genotek Inc., a subsidiary of OraSure Technologies.

GRAVITY Co., Ltd. (GRVY) stock surged 4.18 percent to $2.74 in aftermarket trading. The company stock plunged nearly 6 percent in regular trade.

Pacific Biosciences of California, Inc. (PACB) stock advanced 3.83 percent to $3.52 in aftermarket session.

Digital River, Inc. (DRIV) stock advanced 3.37 percent to $19.03 in post market trading after investor George Soros disclosed in an SEC filing that he has taken a passive 7.98 percent stake in the e-commerce software provider, Forbes reported.

Saba Software, Inc. (SABA) stock gained 3.12 percent to $10.25 in post market trading. The company stock slumped more than 18 percent in regular trade as Saba Software announced Wednesday that it is delaying its third quarter fiscal year 2012 earnings release and investor conference call to allow the Company additional time to complete an internal review of the accounting treatment of certain international transactions.

Aceto Corp. (ACET) stock gained 3.04 percent to $9.83 in aftermarket session.

Losers

Xyratex Ltd. (XRTX) stock slumped 8.75 percent to $16.26 in post market session. The company reported first quarter net income of 10.9 million or $0.38 per share compared to $4.7 million or $0.15 per share in the same period a year-ago. Revenue was $295.7 million, down from $360.5 million in the same period last year and against analysts' estimation of $316.5 million.

VIVUS, Inc. (VVUS) stock plunged 3.67 percent to $20.50 in aftermarket session. The company stock surged nearly 5 percent in regular session.

American Realty Capital Trust, Inc. (ARCT) stock declined 3.4 percent to $9.88 in post market session. ARCT announced that it has voluntarily withdrawn its Registration Statement on Form S-11 that was filed on Feb 15, 2012 with the United States Securities and Exchange Commission to register additional shares of its common stock in a secondary offering under the Securities Act of 1933, as amended.

Savient Pharmaceuticals Inc. (SVNT) stock fell 2.8 percent to $2.08 in aftermarket session.

Research in Motion Ltd. (RIMM) stock fell 2.4 percent to $13.40 in aftermarket trading. The company swung to fourth quarter net loss of $125 million or $0.24 per share compared to net profit of $934 million or $1.78 per share in the same period a year-ago. Revenue was $4.2 billion, down from 5.6 billion in the same period a year-earlier and against analysts' estimation of $4.54 billion.

Orexigen Therapeutics, Inc. (OREX) stock fell 1.98 percent to $4.45 in aftermarket session. The stock has a 52-week low of $1.22, a 52-week high of $5.14 and $307.55 million in market capitalization.

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