The top after-market NASDAQ gainers Wednesday were: CE Franklin Ltd Inc, Envivio Inc, Zumiez Inc, Datalink Corporation and 21Vianet Group Inc.

The top after-market NASDAQ losers were: F5 Networks Inc, BioMarin Pharmaceutical Inc, Tivo Inc, Pacific Biosciences of California Inc and American Superconductor Corporation.

Gainers

CE Franklin Ltd (CFK) shares climbed 36.71 percent to $12.40 in after-market session Wednesday. The company shares trading in the red during market hours started surging after the company had announced that National Oilwell Varco Inc's subsidiary, NOV distribution services, would acquire CE Franklin for consideration of CAD$12.75 in cash per common share.

The total consideration payable under the arrangement is approximately CAD$240 million, according to a Business Wire press release.

Envivio Inc (ENVI) shares surged 3.37 percent to 8.60 in after-market hours trading Wednesday. The company Wednesday reported $0.12 earnings per share which is better than analysts' estimate of $0.18. The company reported $13.4-million revenue against analysts' estimate of $13 million in the first quarter.

Zumiez Inc (ZUMZ) shares advanced 2.47 percent to $35.63 in post-market trading. Teen apparel chain Zumiez announced in after-market hours Wednesday that its May comps surged 13.7 percent, double the expectations.

Datalink Corporation (DTLK) shares gained 2.22 percent and reached $10.20 in after-market hours trading. The company shares traded 5.31 percent down in the Wednesday regular session.

Shares of 21Vianet Group Inc ( VNET) rose 2.19 percent in the post-market session to close at $11.69.  

Losers

F5 Networks Inc (FFIV) shares lost 4.91 percent in post-market hours to reach $102.26 after the Seattle-based company announced the resignation of Mark Anderson, the company's executive vice president of worldwide sales. Dave Feringa, currently senior vice president, Americas Sales, would take over from Anderson as the company's executive vice president of worldwide sales, RTTNews reported.

BioMarin Pharmaceutical Inc (BMRN) shares declined 3.37 percent to $37.00 in post-market hours. The company is offering to sell 6,500,000 shares of its common stock in an underwritten public offering and has granted the underwriters a 30-day option to purchase an additional 650,000 shares of common stock.

Tivo Inc (TIVO) reported $0.17 earnings per share in the first quarter, lower than the analysts' estimate of $0.15. Revenue for the quarter stood at $54.5 million versus the analysts' estimate of $54.89 million.

Pacific Biosciences of California Inc (PACB) traded 2.56 percent lower at $2.28 in post-market session after losing 1.68 percent in the regular trading session.

American Superconductor Corporation (AMSC) shares plunged 2.06 percent to $3.80 in post-market session after gaining 2.37 percent in the regular session.