The top after-market Nasdaq gainers Wednesday were Flow International Corporation, Halozyme Therapeutics Inc, Heartland Express Inc, Array BioPharma Inc and CalAmp Corp Inc.

The top after-market Nasdaq losers were: Synta Pharmaceuticals Corp, Splunk Inc, Grand Canyon Education Inc, Synageva BioPharma Corp and Seagate Technology.

Gainers

Flow International Corporation (FLOW) shares climbed 14.43 percent to $ 3.33 in after-hours trading. The company reported Wednesday a stronger growth rate and earnings compared to the previous fiscal year for the fourth quarter ending April 2012. Consolidated revenue growth was 17 percent at $253.8 million, compared to $216.5 million in the prior fiscal year. Net income for fiscal year 2012 was $9.4 million or $0.20 per share, compared to a net income of $0.8 million or $0.02 per share in the previous fiscal year.

Shares of Halozyme Therapeutics Inc (HALO) rose 4.80 percent in post-market session to close at $9.38. Halozyme Therapeutics Inc is a biopharmaceutical company developing and commercializing products that advance patient care. The company shares have a 52-week low of $5.54, a 52-week high of $13.50 and $1.01 billion in market capitalization.   

Heartland Express Inc (HTLD) shares advanced 4.74 percent to $14.35 in post-market trading. Its shares have a 52-week low of $12.75, a 52-week high of $17.37 and $1.18 billion in market capitalization.   

Array BioPharma Inc (ARRY) shares surged 4.29 percent to $3.65 in after-hours trading Wednesday. The biotechnology company's shares have a 52-week low of $1.58, a 52-week high of $4.10 and $311.98 million in market capitalization.   

CalAmp Corp Inc (CAMP) shares gained 4.06 percent and reached $8.71 in after-hours trading.

Losers

Synta Pharmaceuticals Corp (SNTA) slumped 22.76 percent to $5.60 in post-market session Wednesday. The biopharmaceutical company has a 52-week low of $3.02, a 52-week high of $8.50 and $417.88 million in market capitalization.   

Splunk Inc (SPLK) shares plunged 3.57 percent to $ 27.00 in post-market session. The company announced late Wednesday that it has filed a registration statement with the U.S. Securities and Exchange Commission (the SEC) for a proposed public offering of shares of its common stock. Splunk will not receive any proceeds from the sale of the shares and all shares are being sold by its existing stock holders.

Grand Canyon Education Inc (LOPE) shares lost 2.93 percent in after-hours trading to reach $ 19.85. Its shares gained 2.15 percent in regular market trading.  

Synageva BioPharma Corp (GEVA) stocks dropped 2.93 percent to $ 19.85 in after-hours trading. The Internet business company stocks have a 52-week low of $34.12, a 52-week high of $52.78 and $3.71 billion in market capitalization.   

Seagate Technology (STX) shares declined 2.20 percent to $ 23.99 in after-hours trading. The hardware company has a 52-week low of $10.04, a 52-week high of $41.27 and a market capitalization of 849.81 million.