The top after-market NYSE gainers Friday were Quicksilver Resources, Elan Corp, Tetra Technologies, Broadridge Financial Solutions and Chimera Investment Corp. The top after-market NYSE losers were CYS Investments, Nucor Corp, Parker Drilling and McEwen Mining.

Gainers

Quicksilver Resources Inc. (NYSE:KWK) shares surged 6.60 percent to $2.26 in post-market trading after climbing more than 14 percent in regular trading.

Elan Corp. plc (NYSE:ELN) shares surged 5.58 percent to $12.10 in post-market trading. The company provided an update on the Tysabri Restructuring Transaction announced Feb. 6 and further information regarding the recently announced $1billion share repurchase program, Friday.

Tetra Technologies Inc. (NYSE:TTI) shares gained 3.08 percent to $9.36 in post-market trading. The stock has a 52-week low of $5.35, a 52-week high of $9.81 and $708.98 million in market capitalization.

Broadridge Financial Solutions Inc. (NYSE:BR) shares advanced 2.61 percent to $24.33 in post-market trading. The stock has a 52-week low of $19.75, a 52-week high of $24.69 and $2.89 billion in market capitalization.

Chimera Investment Corp. (NYSE:CIM) shares rose 2.58 percent to $3.18 in post-market trading. The stock has a 52-week low of $1.81, a 52-week high of $3.23 and $3.18 billion in market capitalization.

Losers

CYS Investments Inc. (NYSE:CYS) shares plunged 2.17 percent to $11.74 in post-market trading. The company announced Friday that its Board of Directors declared a quarterly dividend of $0.32 per share of common stock for the first quarter of 2013, payable Apr. 17 to common stock stockholders of record as of March 25.

Nucor Corp. (NYSE:NUE) shares declined 1.72 percent to $46.83 in post-market trading. The stock has a 52-week low of $34.23, a 52-week high of $48.60 and $15.14 billion in market capitalization.

Parker Drilling Co. (NYSE:PKD) shares declined 1.70 percent to $4.72 in post-market trading. The company stock surged more than 3 percent in regular trading.

McEwen Mining Inc. (NYSE:MUX) shares fell 1.52 percent to $2.60 in post-market trading. The company stock surged nearly 4 percent in regular trading.

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