Cabot Oil, Merck, Pioneer Natural, Viacom: U.S. Equity Movers

Shares of the following companies had unusual moves in U.S. trading. Stock symbols are in parentheses and prices are as of 4 p.m. in New York.

Energy producers rallied as crude oil rose to the highest level in more than three months amid optimism a recovering economy will fuel demand. Cabot Oil & Gas Corp. (COG) advanced 7.7 percent to $86.55. Pioneer Natural Resources Co. (PXD) climbed 6.7 percent to $92.12.

Advance Auto Parts Inc. (AAP) gained 4.7 percent, the most since Aug. 11, to $69.51. The auto parts retailer based in Roanoke, Virginia, raised its full-year earnings forecast to at least $4.90 a share, exceeding the average analyst projection of $4.69 in a Bloomberg survey.

ATP Oil & Gas Corp. (ATPG US) slumped 14 percent to $7.25, the lowest price since Oct. 4. The Houston-based may not be able to make a May interest payment on $1.5 billion in notes after the company’s crude and natural-gas output plunged, Vivek Pal, an analyst at Knight Capital Group Inc. said.

Cisco Systems Inc. (CSCO) jumped 5.7 percent, the most in the Dow Jones Industrial Average, to $18.61. The world’s biggest maker of networking equipment reported profit and sales that exceeded analysts’ estimates, bolstered by a turnaround effort and demand for data centers. The San Jose, California- based company was raised to “buy” at Citigroup Inc. (C) and Deutsche Bank AG.

Computer Sciences Corp. (CSC) had the biggest retreat in the Standard & Poor’s 500 Index, sliding 9.5 percent to $25.24. The provider of computer services to companies and U.S. government agencies was cut to “underweight” from “neutral” by JPMorgan Chase & Co. (JPM)

Dynavox Inc. (DVOX) rose the most in the Russell 2000 Index, surging 21 percent to $4.08. The seller of speech software for people with learning disabilities reported first- quarter sales of $26.2 million, 13 percent higher than the average analyst estimate in a Bloomberg survey.

EnerSys (ENS) climbed 19 percent, the most since December 2008, to $26.22. The Reading, Pennsylvania-based maker and distributor of industrial batteries forecast third-quarter profit excluding some items of 67 cents a share at least. That topped the average analyst estimate of 63 cents from a Bloomberg survey.

Green Mountain Coffee Roasters Inc. (GMCR) tumbled 39 percent, the most in the Russell 1000 Index, to $40.89. The maker of the Keurig single-cup brewing system reported fourth- quarter sales that trailed analysts’ estimates amid changes in wholesale customers’ buying habits.

Huntington Ingalls Industries Inc. (HII US) jumped 6.3 percent, the most since March 31, to $31. The U.S. Navy’s largest builder of surface warships reported third-quarter profit excluding some items of $1.05 a share, beating the average analyst estimate by 24 percent, according to Bloomberg data.

Intralinks Holdings Inc. (IL) declined 13 percent to $4.80, the lowest price since its August 2010 initial public offering. The software maker was cut to “hold” from “buy” at Deutsche Bank AG.

Merck & Co. (MRK US) climbed 3.5 percent, the most since Aug. 11, to $34.97. The second-biggest U.S. drugmaker raised its dividend for the first time since 2004 and emphasized drug discovery in a meeting with analysts today.

Opnet Technologies Inc. (OPNT) dropped 21 percent, the most since November 2007, to $35.68. The management software maker reported second-quarter sales that trailed analysts’ estimates.

Pegasystems Inc. (PEGA) sank 21 percent, the most since August 2010, to $29.19. The developer of customer relationship management software reported third-quarter earnings excluding some items of 15 cents a share, missing the average analyst estimate by 52 percent, according to Bloomberg data.

Quad Graphics Inc. (QUAD US) tumbled 25 percent to $13.77, the lowest price since at least July 2010. The printing company reported third-quarter adjusted earnings of 80 cents a share, missing the average analyst estimate by 6 cents.

Silver Standard Resources Inc. (SSRI) slumped 21 percent, the most since July 2002, to $15.13. The silver producer cut the resource and reserve estimates for its Pirquitas mine in Argentina and reduced its 2011 silver production forecast.

Vertex Pharmaceuticals Inc. (VRTX) climbed 3.6 percent to $31.98, the biggest gain since Oct. 20. The drugmaker was raised to “equalweight” from “underweight” at Morgan Stanley. (MS)

Viacom Inc. (VIA/B) (VIA/B US) rallied 8.2 percent, the biggest gain in the S&P 500, to $43.61. The owner of the MTV network and Paramount Pictures reported fourth-quarter profit and revenue that rose more than analysts estimated and boosted its stock- repurchase program by $6 billion.

Wynn Resorts Ltd. (WYNN) fell 3.5 percent to $119.57, the lowest price since Oct. 4. Macquarie Group Ltd. said the velocity of money at the company’s Macau business may be slowing.

To contact the reporter on this story: Inyoung Hwang in New York at ihwang7@bloomberg.net

To contact the editor responsible for this story: Nick Baker at nbaker7@bloomberg.net

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