The top after-market Nasdaq gainers Monday were Skullcandy Inc., Amicus Therapeutics Inc., Supernus Pharmaceuticals Inc., ACADIA Pharmaceuticals Inc. and Electronic Arts Inc., while the top after-market Nasdaq losers were Intersections Inc., Lululemon Athletica Inc., USA Mobility Inc. and TICC Capital Corp.

Gainers

Skullcandy Inc. (NASDAQ:SKUL) shares surged 6.00 percent to $5.65 in post-market trading. The company announced that its board of directors has appointed Hoby Darling as President and Chief Executive Officer effective immediately.

Amicus Therapeutics Inc. (NASDAQ:FOLD) shares climbed 4.35 percent to $3.60 in post-market trading. The company stock has a 52-week average of $2.47-$6.89 and a market capitalization of $170.60 million.

Supernus Pharmaceuticals Inc. (NASDAQ:SUPN) shares advanced 4.20 percent to $5.21 in post-market trading. The company stock has a 52-week average of $4.30-$16.68 and a market capitalization of $122.65 million.

ACADIA Pharmaceuticals Inc. (NASDAQ:ACAD) shares gained 3.24 percent to $6.38 in post-market trading. Apparently, analysts at Jefferies Group initiated coverage on shares of ACADIA in a research report issued to clients and investors Monday. The firm set a “buy” rating on the stock.

Electronic Arts Inc. (NASDAQ:EA) shares rose 2.51 percent to $19.18 in post-market trading. The company said Monday its chief executive, John Riccitiello, resigned after his efforts to respond to changes in the videogame industry failed to boost the company's earnings or stock. The videogame publisher Monday said Chairman Larry Probst, a previous EA chief executive, would become executive chairman while the board searches for a permanent replacement for Riccitiello.

Losers

Intersections Inc. (NASDAQ:INTX) shares declined 14.48 percent to $9.45 in post-market trading. The company announced Monday that its fourth-quarter earnings dropped sharply as it lost subscribers. It reported fourth quarter net income of $0.08 per share, down from $0.22 per share a year ago. Revenues were $84.4 million, compared to $94.1 million last year. The company expects revenue in 2013 to be about 10 percent to 15 percent lower, as compared to 2012.

Lululemon Athletica Inc. (NASDAQ:LULU) shares dropped 5.92 percent to $62.00 in post-market trading. The company announced late Monday that its first quarter earnings will be significantly impacted after large shipments of its iconic yoga pants were deemed to be too see-through for the store’s standards. Revenue for the quarter is now expected to be in the range of $10 million to $20 million below its previous forecast of $353 million.

USA Mobility Inc. (NASDAQ:USMO) shares slumped 5.02 percent to $12.10 in post-market trading. The company announced after the bell Monday that it has delayed reporting its operating results for the fourth quarter and year ended Dec. 31, 2012 to address a material weakness in the design of internal control over financial reporting relating to the software revenue recognition process.

TICC Capital Corp. (NASDAQ:TICC) shares fell 2.58 percent to $10.20 in post-market trading. The company Monday commenced a public offering of 3 million common shares. The company also intends to grant the underwriters an option to purchase up to an additional 450,000 common shares.