The top after-market NYSE gainers Tuesday were Pandora Media, WellPoint, AuRico Gold Inc, Navios Maritime Partners and H.J. Heinz Co. The top after-market NYSE losers were Dycom Industries, Imax Corp, Graphic Packaging Holding, RadioShack Corp and 3D Systems Corp.

Gainers

Pandora Media, Inc. (P) shares surged 4.32 percent to $10.62 in post-market trading. The company is expected to report the second quarter net profit of $0.12 per share on revenues of $100.9 million after market closes Wednesday.

WellPoint Inc. (WLP) shares surged 3.31 percent to $59.29 in post-market trading. The company announced that its Chief Executive Officer Angela F. Braly stepped down from her post Tuesday and the search for a candidate to succeed Braly had started. John Cannon, WLP's Executive Vice President, General Counsel, Corporate Secretary and Chief Public Affairs Officer, would serve as interim president and CEO, the company said.

AuRico Gold Inc. (AUQ) shares gained 2.52 percent to $6.97 in post-market trading. The stock has a 52-week low of $6.06, a 52-week high of $12.79 and $1.92 billion in market capitalization.

Navios Maritime Partners LP (NMM) shares advanced 1.83 percent to $14.47 in post-market trading.

H.J. Heinz Co. (HNZ) shares rose 1.64 percent to $58.35 in post-market trading. The company announced Tuesday that its Board of Directors had declared quarterly dividends on both common and preferred stock.

Losers

Dycom Industries, Inc. (DY) shares slumped 12.66 percent to $16.49 in post-market trading. The company reported the fourth quarter net profit of $0.39 per share, up from $0.38 per in the same period last year but fell short of analysts' estimate of $0.41 per share.

Imax Corp. (IMAX) shares plunged 2.57 percent to $20.33 in post-market trading. The stock has a 52-week low of $12.57, a 52-week high of $26.68 and $1.38 billion in market capitalization.

Graphic Packaging Holding Co. (GPK) shares fell 2.48 percent to $5.50 in post-market trading. The stock has a 52-week low of $3.05, a 52-week high of $5.89 and $2.22 billion in market capitalization.

RadioShack Corp. (RSH) shares declined 2.01 percent to $2.44 in post-market trading.

3D Systems Corp. (DDD) shares fell 1.72 percent to $42.32 in post-market trading. The company stock surged more than 4.5 percent in regular trading.