The top aftermarket NYSE gainers Monday were: EnergySolutions, Rackspace Hosting, Health Management Associates, Excel Maritime Carriers, Michael Kors Holdings, Nielsen Holdings, HyperDynamics Corp, Magnum Hunter Resources Corp and Superior Energy Services.

EnergySolutions Inc. (ES) shares climbed 13.37 percent to $4.75 in post market trading session.

Rackspace Hosting Inc. (RAX) shares surged 6.85 percent to $52.60 in post market trading session. Its fourth quarter net income surged to $25.0 million or $0.18 per share from $13.5 million or $0.10 per share in the same period last year, while analysts’ expected net profit of $0.15 per share.

Health Management Associates Inc. (HMA) shares gained 5.07 percent to $7.25 in aftermarket trading session. The company reported fourth quarter net profit of $30.85 million or $0.13 per share compared to $28.18 million or $0.11 per share in the same period a year earlier. HMA also affirmed its diluted earnings per share from continuing operations objective range for fiscal year 2012 to be between $0.80 and $0.90.

Excel Maritime Carriers Ltd. (EXM) shares advanced 3.72 percent to $2.23 in post market trading session. The company stock climbed nearly 14 percent in regular trading session on news that EXM has entered into four new period charter agreements for four of its Kamsarmax vessels.

Michael Kors Holdings Ltd. (KORS) shares gained 3.36 percent to $34.74 in aftermarket trading session. The company is expected to report third quarter net profit of $0.08 per share before the markets open on Tuesday.

Nielsen Holdings N.V. (NLSN) shares rose 3.31 percent to $28.35 in post market trading session. The company stock declined more than 3 percent in regular trading session.

HyperDynamics Corp. (HDY) shares gained 3.15 percent to $2.29 in aftermarket trading session. The company announced that it has completed the drilling of the Sabu-1 exploration well on its concession offshore Guinea-Conakry. The Sabu-1 well was drilled to a depth of 11,844 feet in a water depth of 2,329 feet.

Magnum Hunter Resources Corp. (MHR) shares gained 2.97 percent to $6.59 in post market trading session after gaining more than 3 percent in regular session.

Superior Energy Services Inc. (SPN) shares gained 2.95 percent to $28.88 in post market trading session. The stock has a 52-week low of $22.19, a 52-week high of $42.87 and $4.35 billion in market capitalization.

Nyse Management