Nasdaq
Commuters pass by the NASDAQ Market site in New York, May 21, 2012. REUTERS

The top after-market Nasdaq gainers Tuesday were Accuray Inc, Digital Generation Inc, Santarus, Facebook Inc and Applied Micro Circuits Corporation.

The top after-market Nasdaq losers were Globecomm Systems, Xyratex Ltd, Education Management Corporation, STEC Inc and Lattice Semiconductor Corporation.

Gainers

Accuray Inc (ARAY) shares climbed 5.51 percent to $5.98 in post-market trading. The company shares declined 5.34 percent in regular trading Tuesday.

Digital Generation Inc (DGIT) shares surged 5.00 percent to $11.55 in post-market trading. The company shares have a 52-week trading range of $7.51 - $20.98 and a market capitalization of 303.62 million.

Santarus, Inc. (BZH) shares advanced 3.72 percent to $8.09 in post-market trading after the biopharmaceutical company had announced that its Phase III clinical study to evaluate the safety and efficacy of the investigational drug, Rifamycin SV MMX, met the primary endpoint.

Facebook Inc (FB) shares rose 3.45 percent to $20.10 in post-market trading. Company's CEO Mark Zuckerberg made a public appearance at the TechCrunch Disrupt Conference in San Francisco Tuesday and spoke about the progress the company achieved in retooling itself to meet the mobile era requirements and about the progress in developing a search platform for FB.

Applied Micro Circuits Corporation (AMCC) shares gained 3.23 percent to $5.53 in post-market trading. The company shares lost nearly 3.25 percent in regular trading Tuesday.

Losers:

Globecomm Systems (GCOM) shares plunged 21.05 percent to $ 10.50 in post-market trading. The company shares lost nearly 3.25 percent in regular trading Tuesday. The shares dropped after the company forecast its fiscal year 2013 revenue below analysts' current consensus estimate. The company expects consolidated revenues to be between $340 and $360 million.

Xyratex Ltd (XRTX) shares plunged 16.85 percent to $8.93 in post-market trading. The company announced Tuesday that that third quarter revenue would miss its forecast as demand for its data storage products from enterprise customers fell, sending its shares down 25 percent in extended trading, Reuters reported. Xyratex slashed its third quarter revenue to be between $271 million and $276 million, down from its prior forecast of $313 million to $373 million.

Education Management Corporation (EDMC) shares declined 3.33 percent to $5.13 in post-market trading. The company stock gained more than 12 percent in regular trading.

STEC Inc (STEC) shares fell 6.79 percent to $7.00 in post-market trading. The stock declined after the company had announced that PricewaterhouseCoopers LLP decided to discontinue as its independent registered public accounting firm.

Lattice Semiconductor Corporation (LSCC) shares declined 2.94 percent to $19.50 in post-market trading. The company shares gained nearly 7 percent in regular trading.