The top after-market NYSE gainers Wednesday were Halcon Resources Corp, Gol Linhas Aereas Inteligentes, Walter Energy, Accretive Health and MGIC Investment Corp. The top after-market NYSE losers were Managed High Yield Plus Fund, Pimco Corporate & Income Opportunity, EMC Corp and Lehigh Gas Partners LP.

Gainers

Halcon Resources Corp. (HK) shares surged 1.78 percent to $6.86 in post-market trading. The stock has a 52-week low of $5.26, a 52-week high of $13.35 and $1.74 billion in market capitalization.

Gol Linhas Aereas Inteligentes SA (GOL) shares gained 1.64 percent to $6.46 in post-market trading. The stock has been surging since the company announced its plan to segregate its Smiles mileage points program.

Walter Energy Inc. (WLT) shares rose 1.38 percent to $34.60 in post-market trading. The stock has a 52-week low of $28.01, a 52-week high of $76.95 and $2.13 billion in market capitalization.

Accretive Health Inc. (AH) shares gained 1.27 percent to $11.90 in post-market trading. The company stock plunged more than 3 percent in regular trading.

MGIC Investment Corp. (MTG) shares advanced 1.15 percent to $2.64 in post-market trading after climbing more than 9 percent in regular trading.

Losers

Managed High Yield Plus Fund Inc. (HYF) shares plunged 2.38 percent to $2.05 in post-market trading.

Pimco Corporate & Income Opportunity Fund (PTY) shares fell 0.95 percent it $19.74 in post-market trading. The stock has a 52-week low of $17.06, a 52-week high of $20.85 and $1.36 billion in market capitalization.

EMC Corp. (EMC) shares fell 0.87 percent to $25.11 in post-market trading. The stock has a 52-week low of $21.39, a 52-week high of $30.00 and $53.36 billion in market capitalization.

Lehigh Gas Partners LP (LGP) shares declined 0.92 percent to $18.30 in post-market trading. Analysts at Robert W. Baird Tuesday reaffirmed an “outperform” rating on the shares of LGP with a price target of $26.00.