The top after-market Nasdaq gainers Monday were HealthStream Inc, Sanmina-SCI Corporation, The Wet Seal Inc, Amedisys Inc and Stamps.com Inc.

The top after-market Nasdaq losers were Volterra Semiconductor Corporation, Transcept Pharmaceuticals Inc, Grand Canyon Education Inc, Apollo Group Inc and SIGA Technologies Inc.

Gainers

HealthStream  Inc (HSTM) shares climbed 11.73 percent to $26.00 in after-hours trading Monday. The company's shares surged after it reported second quarter earnings that met market expectations. The company reported a 23 percent jump in revenues to $25.8 million on year-on-year basis and announced EPS of $0.9 which met the analysts' expectations.

Shares of Sanmina-SCI Corporation (SANM) rose 11.56 percent in the post-market to close at $8.01. The company reported third quarter earnings per share that were below the analysts' expectations. The company revenues declined from $1.67 billion to $1.55 billion, on a year-on-year basis, but were above the analysts' expectations.

The Wet Seal Inc (WTSLA) shares advanced 7.89 percent to $2.87 in post-market trading. The company shares had declined 10.14 percent in regular trading Monday.

Amedisys Inc (AMED) shares gained 6.21 percent and reached $13.85 in after-hours trading. The company stocks slumped 5.85 percent in regular trade Monday.  

Stamps.com Inc (STMP) shares surged 3.27 percent to $19.04 in after-hours trading Monday. The shares of the company dropped 6.21 percent in regular trade Monday.  

Losers

Volterra Semiconductor Corporation (VLTR) shares slumped 12.77 percent to $22.00 in the post-market Monday. The company announced its second quarter results Monday and reported earnings per share of $0.32, missing the analysts' expectation of $0.34 by $0.02. The company's revenue for the quarter was up 4.5 percent on a year-over-year basis.  

Transcept Pharmaceuticals (TSPT) shares plunged 8.60 percent to $6.06 in the post-market. The company shares have a 52-week low of $2.58 and 52-week high of $12.99 and market capitalization of 122.91 million.

Grand Canyon Education Inc (LOPE) shares lost 7.75 percent in after-hours trading to reach $17.50.

Apollo Group Inc (ICUI) shares dropped 7.40 percent to $26.78 in after-hours trading. The company shares have a 52-week low of $28.67 and 52-week high of $58.29 and market capitalization of 3.28 billion.

SIGA Technologies Inc (SIGA) shares declined 6.98 percent to $2.80 in after-hours trading. The company shares have a 52-week low of $1.78 and 52-week high of $8.58 and market capitalization of 155.43 million.