The top after-market Nasdaq gainers Friday were Meru Networks Inc, Lincoln Electric Holdings Inc, Amkor Technology Inc and Amarin Corporation Plc.

The top after-market Nasdaq losers were WisdomTree Investments Inc, Alaska Communications Systems Group Inc, Ironwood Pharmaceuticals Inc and Mid-Con Energy Partners LP.

Gainers

Meru Networks Inc (MERU) shares climbed 3.40 percent to $2.74 in after-hours trading. The company reported 5 percent increase in second quarter revenues to $24.5 million.   The company shares rose over 56 percent in regular trading Friday.

Lincoln Electric Holdings Inc (LECO) rose 2.81 percent in post-market trading to close at $45.69. The company declared a quarterly cash dividend of $0.17 per share, payable October 15, 2012, to holders of record as of September 28, 2012.

Amkor Technology Inc (AMKR) shares advanced 2.70 percent to $5.32 in post-market trading. The company shares rose 5.50 percent in regular trading and the company has $ 871.73 million in market capitalization.

Amarin Corporation PLC (AMRN) shares gained 2.52 percent and reached $13.85 in after-hours trading. In a flash note to clients Friday, Roth Capital Partners' analyst Joseph Pantginis says Thursday's FDA approval for Amarin Corporation's Vascepa bodes well for Neptune Technologies & Bioressources' underlying and growing core NKO business as well as the pharmaceutical opportunity with Acasti's CaPre, a Reuters report said.

Losers

WisdomTree Investments Inc (WETF) slumped 3.49 percent to $6.36 in post-market trading Friday. The company reported net income of $0.1 million in the second quarter of 2012, down from $0.7 million in the second quarter of 2011 and $1.1 million in the first quarter of 2012.

Alaska Communications Systems Group Inc (ALSK) shares declined 1.77 percent to $2.14 in after-hours trading.  The company stock has a 52-week low of $1.73, a 52-week high of $7.85 and $99.16 million in market capitalization.   

Ironwood Pharmaceuticals Inc (IRWD) shares lost 1.64 percent in after-hours trading to reach $13.20. The company shares have a 52-week low of $9.97, a 52-week high of $15.92 and 1.44 billion in market capitalization.

Mid-Con Energy Partners LP (MCEP) shares dropped 1.52 percent to $21.56 in after-hours trading. The company shares have a 52-week low of $17.25, a 52-week high of $25.18 and 397.29 million in market capitalization.