The top after-market NASDAQ Stock Market losers are: PDF Solutions, Oclaro, Research In Motion, Ensign Group, Deckers Outdoor, Internap Network Services, CoStar Group, CROCS, Oncothyreon, TeleCommunication Systems, and Microsoft.

PDF Solutions Inc. (PDFS) stock plunged 15.20 percent to $5.80 in the after-market trading. Loss for the first quarter widened to $577,000 or $0.02 per share from $296,000 or $0.01 per share last year. Adjusted profit was $622,000 or $0.02 per share, down from $1.7 million or $0.06 per share last year. Revenue declined 2 percent to $15 million.

Oclaro, Inc. (OCLR) stock plummeted 11.69 percent to $10.35 in the after-market trading, as it guided fourth quarter revenue below consensus. The company expects fourth quarter revenue of $105 million to $115 million, while Street predicts $117.28 million. The company anticipates fourth quarter adjusted gross margin of 21 percent to 24 percent and adjusted EBITDA of negative $1.5 million to negative $6.5 million.

Oclaro reported third quarter adjusted loss of $4.07 million or $0.08 per share, compared to a profit of $2.6 million or $0.06 per share last year. Revenue rose to $116.58 million from $101.15 million. Analysts had expected profit of $0.06 per share on revenue of $116.49 million.

Research In Motion Ltd. (RIMM) stock fell 11.12 percent to $50.30 in the after-market trading, as it cut guidance for the first quarter, expecting weaker-than-expected shipment volumes of BlackBerry smartphones and a shift in the projected mix of devices shipped towards handsets with lower average selling prices.

The BlackBerry maker lowered its first quarter earnings guidance to range of $1.30 to $1.37 per share from previous forecast of $1.47 to $1.55 per share. The company now expects revenue for the first quarter to be slightly below the previous guidance range of $5.2 billion to $5.6 billion. Street analysts predict profit of $1.48 per share on revenue of $5.44 billion for the first quarter.

For the fiscal year 2012, Research In Motion reduced its earnings outlook to about $7.50 per share from previous forecast in excess of $7.50 per share, while Street predicts $6.87 per share. The company also expects strong revenue growth in the third and fourth quarters of the fiscal year, due to new product launches and prudent cost management.

The Ensign Group, Inc. (ENSG) stock fell 10.31 percent to $28.44 in the after-market trading.

Deckers Outdoor Corp. (DECK) stock tumbled 7.88 percent to $87.01 in the after-market trading, as it expects second quarter loss of $0.25 per share. The company expects second quarter revenue growth of about 4 percent over last year. Street predicts profit of $0.05 per share on revenue of $144.84 million for the second quarter. For the full year 2011, the company raised its earnings growth guidance to about 13 percent from 10 percent, and revenue growth outlook to about 21 percent from 20 percent. Analysts project earnings of $4.56 per share on revenue of $1.21 billion for the year.

Deckers Outdoor reported first quarter earnings of $19.2 million or $0.49 per share, compared to $17.9 million or $0.46 per share last year. Sales grew 31.4 percent to $204.9 million. Analysts had expected earnings of $0.46 per share on revenue of $202.77 million.

Internap Network Services Corp. (INAP) stock slid 7.54 percent to $7.60 in the after-market trading. Loss for the first quarter widened to $1.5 million or $0.03 per share from $0.3 million or $0.01 per share last year. Normalized net loss was $0.4 million or $0.01 per share, compared to a profit of $0.7 million or $0.01 per share last year. Revenue declined to $59.4 million from $63.4 million. Analysts had expected earnings of $0.02 per share on revenues of $60.46 million.

CoStar Group Inc. (CSGP) stock fell 6.18 percent to $61.03 in the after-market trading.

CROCS Inc. (CROX) stock slid 6.06 percent to $20 in the after-market trading, as it guided second quarter below Street view. The company expects second quarter earnings of about $0.43 per share and revenue of about $280 million, while Street predicts profit of $0.44 per share on revenue of $281.64 million. The company reported first quarter earnings of $21.5 million or $0.24 per share, up from $5.7 million or $0.07 per share last year. Revenue grew 35.9 percent to $226.7 million. Analysts had expected earnings of $0.20 per share on revenue of $216.10 million for the first quarter.

Further, the company said it appointed Jeff Lasher as the company's chief financial officer, effective April 28. After an extensive search, the management team and board of directors came to the unanimous decision that Jeff was the best candidate to serve as our Chief Financial Officer. In addition to his financial background and prior experience with publicly held companies, Jeff brings a deep understanding of our global business to this critical role, said John McCarvel, President and Chief Executive Officer of CROCS.

Oncothyreon Inc (ONTY) stock declined 5.87 percent to $4.65 in the after-market trading. The company announced its intention to offer shares of its common stock in an underwritten public offering. The company also expects to grant the underwriters a 30-day option to purchase up to an additional 15 percent of the shares of common stock offered in the public offering to cover over-allotments, if any.

The proceeds of the offering will primarily be used to fund the development of PX-866, Oncothyreon's PI-3 Pan-isoform irreversible Kinase inhibitor, and ONT-10, Oncothyreon's proprietary follow-on vaccine to Stimuvax. Stimuvax, currently in a Phase 3 pivotal trial, is a vaccine for patients with non-small cell lung cancer and is partnered with Merck KGaA. The offering proceeds may also be used for general corporate purposes. Cowen and Company, LLC is acting as the sole book-running manager for the offering, and Wedbush PacGrow Life Sciences is acting as co-manager.

TeleCommunication Systems Inc. (TSYS) stock decreased 5.83 percent to $4.20 in the after-market trading. Profit for the first quarter was $2.06 million or $0.04 per share, down from $5.68 million or $0.08 per share last year. Adjusted earnings declined to $8.59 million or $0.13 per share from $9.32 million or $0.14 per share. Revenue was $90.37 million, compared to $90.92 million last year. Analysts had expected profit of $0.02 per share on revenue of $103.58 million.

Microsoft Corp. (MSFT) stock moved down 1.42 percent to $26.33 in the after-market trading. Profit for the third quarter was $5.2 billion or $0.61 per share, compared to $4.0 billion or $0.45 per share last year. Revenue rose to $16.4 billion from $14.5 billion, driven by strong sales of Office 2010, Xbox and Kinect. Analysts had expected earnings of $0.56 per share on revenue of $16.19 billion.

However, revenue for the company's windows and windows live division fell 4 percent to $4.45 billion, in line with the PC trend. This is the second consecutive quarter that the division's revenue has slipped from the previous year. Earlier this month, Gartner, Inc. (IT) said worldwide PC shipments decreased a marginal 1.1 percent in the first quarter of 2011, the first year-over-year decline in six quarters, reflecting a steady decline in consumer PC demand amid the growing popularity of media tablets.

Microsoft reaffirmed operating expense guidance of $26.9 billion to $27.3 billion for the fiscal 2011. The company also provided preliminary fiscal 2012 operating expense guidance of 3 percent to 5 percent growth from the mid-point of fiscal 2011 guidance, or $28.0 billion to $28.6 billion. Microsoft stopped making specific profit or revenue forecasts in January 2009, citing market volatility.