The top aftermarket NYSE gainers Thursday were: Fortuna Silver Mines, McEwen Mining, E-Commerce China Dangdang, Accretive Health, Collective Brands and Silvercorp Metals Inc. The top aftermarket NYSE losers were: Vocera Communications, Brandywine Realty Trust, Penn Virginia Corp, CPB Inc, Fresh Del Monte Produce and Humana Inc.

Gainers

Fortuna Silver Mines Inc. (FSM) shares surged 3.74 percent to $4.44 in aftermarket session. The company stock plunged more than 3 percent in regular session.

McEwen Mining Inc. (MUX) shares gained 3.41 percent to $4.25 in aftermarket session. The stock has a 52-week low of $2.93, a 52-week high of $9.87 and $1.10 billion in market capitalization.

E-Commerce China Dangdang Inc. (DANG) shares advanced 2.93 percent to $7.73 in post market trading. The company announced that it formed a strategic alliance with Gome Online and launched a B2B2C e-commerce platform in Dangdang's marketplace focusing on electronics and computers products.

Accretive Health, Inc. (AH) shares rose 2.31 percent to $20.05 in post market session. The company stock slumped more than 18 percent in regular session after announcing that it modified an agreement with a Minnesota hospital operator that is expected to negatively impact revenue by $62 million to $64 million in fiscal 2012.

Collective Brands, Inc. (PSS) shares advanced 1.55 percent to $20.30 in post market session. The company stock climbed more than 8 percent in regular trade after South Korean clothing company E-Land Group said it will bid for the retailer, which owns the Payless ShoeSource chain, Bloomberg Reported.

Silvercorp Metals Inc. (SVM) shares rose 1.47 percent to $6.90 in aftermarket trading. The stock has a 52-week low of $5.86, a 52-week high of $16.32 and $1.16 billion in market capitalization.

Losers

Vocera Communications, Inc. (VCRA) shares slumped 11.44 percent to $22.06 in aftermarket session. The company stock climbed more than 18 percent in regular trading.

Brandywine Realty Trust (BDN) shares plunged 5.97 percent to $10.71 in post market trading. The stock has a 52-week low of $6.77, a 52-week high of $12.84 and $1.63 billion in market capitalization.

Penn Virginia Corp. (PVA) shares plunged 5.42 percent to $4.36 in aftermarket session.

CPB Inc. (CPF) shares plunged 4.36 percent to $12.95 in aftermarket session. The company announced that the United States Department of the Treasury (Treasury) plans to offer 2,770,117 shares of the Company's common stock it currently holds in an underwritten public offering.

Fresh Del Monte Produce, Inc. (FDP) shares declined 4.10 percent to $21.78 in aftermarket session. The stock has a 52-week low of $21.26, a 52-week high of $28.11 and $1.31 billion in market capitalization.

Humana Inc. (HUM) shares fell 3.95 percent to $87.93 in aftermarket session. The company stock gained more than 3 percent in regular trade.

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