Affymax, Robbins & Myers, Supervalu, Verizon: 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.

Affymax Inc. (AFFY US) climbed 15 percent, the most since Nov. 22, to $7.99. The biotechnology company developing an experimental anemia drug named its president, John Orwin, to succeed Arlene Morris as chief executive officer and board member effective Feb. 1.

AK Steel Holding Corp. (AKS US) fell 7.4 percent to $15.36 for the biggest loss in the Standard & Poor’s 500 Index. The third-largest U.S. steelmaker was cut to “sell” from “neutral” by Goldman Sachs Group Inc.

U.S. Steel Corp. (X US) declined 4.9 percent to $56.14.

Ardea Biosciences Inc. (RDEA US) gained 9.9 percent to $28.66, the highest price since May 2002. The developer of cancer treatments said a study of its RDEA594 in combination with the current standard of care for the treatment of gout patients showed “positive” results.

Baker Hughes Inc. (BHI US) climbed 3.2 percent, the most since Nov. 18, to $56.60. The world’s third-largest oilfield-services provider was lifted to “buy” from “neutral” at Goldman Sachs Group Inc.

Goldman Sachs also boosted Diamond Offshore Drilling Inc. (DO US), the largest U.S. deep-water oil driller, to “conviction buy” from “sell,” and the stock climbed 4.9 percent to $70.57.

Bottomline Technologies Inc. (EPAY US) fell 3.9 percent, the most since Oct. 4, to $21.20. The maker of financial-management and payment software was cut to “neutral” from “buy” at D.A. Davidson & Co.

Dean Foods Co. (DF US) rallied 11 percent to $9.89, the most in the S&P 500. The biggest U.S. milk-products maker gained after Appaloosa Management LP, the hedge-fund firm founded by billionaire investor David Tepper, disclosed a 7.4 percent stake, making it the second-largest holder.

Dendreon Corp. (DNDN US) advanced 7.9 percent, the most since Aug. 4, to $38.20. The drugmaker reported 2010 revenue of $48 million from its prostate-cancer treatment Provenge and projected sales this year of $350 million to $400 million.

Goodyear Tire & Rubber Co. (GT US) gained 5.1 percent to $12.90 for the third-biggest advance in the S&P 500. The largest U.S. tiremaker was raised to “buy” from “hold” at Citigroup Inc.

Interpublic Group of Cos. (IPG US) advanced 4.7 percent to $11.11, the biggest gain since Oct 11. The New York-based advertising company was rated a new “buy” at Lazard Capital Markets.

Jones Group Inc. (JNY US) fell 7 percent, the most since Oct. 27, to $14.46. The New York-based maker of Nine West shoes was cut to “underweight” from “equal weight” by Morgan Stanley.

JPMorgan Chase & Co. (JPM US) sank 2.9 percent to $43.64 for the second biggest drop in the Dow Jones Industrial Average. The lender fell after US Bancorp (USB US) and Wells Fargo & Co. (WFC US) lost a foreclosure case in Massachusetts’s highest court that will guide lower courts in that state and may influence others in clashes between bank practices and state real estate law.

Bank of America Corp. (BAC US) slumped 1.3 percent to $14.25. Wells Fargo declined 2 percent to $31.50. US Bancorp slipped 0.8 percent to $26.09.

KB Home (KBH US) rose 6.4 percent to $15.25, the highest price since May 19. The Los Angeles-based homebuilder that targets first-time buyers reported an unexpected fourth-quarter profit after cutting costs amid slumping demand for new houses.

Kulicke & Soffa Industries Inc. (KLIC US) advanced 13 percent to $8.66, the highest price since July 13. The maker of semiconductor assembly equipment was raised to “outperform” from “underperform” at Oppenheimer & Co. Corp. (LOCM US) dropped the most in the Russell 2000 Index, tumbling 25 percent to $5.19. The Internet search engine that helps users find local businesses bought iTwango LLC and said fourth-quarter earnings missed its forecast.

Men’s Wearhouse Inc. (MW US) rose 4.8 percent to $25.57, the highest price in a month. The retailer of men’s suits and attire was raised to “overweight” from “equal-weight” at Johnson Rice & Co.

MGM Resorts International (MGM US) climbed 7.4 percent, the most since Nov. 3, to $16.35. Chief Executive Officer James Murren said the company’s hotel room revenue, convention business and gaming revenue are “starting to come back” in an interview with CNBC.

Murphy Oil Corp. (MUR US) declined 4 percent, the most since Aug. 11, to $71.05. The oil producer and refiner said it failed to find hydrocarbons in two of three wells in the Mer Profond Sud permit in the Republic of the Congo. The Turquoise Marine #4 exploration well did find reservoirs with minor accumulation of oil. The total net cost of the program is estimated to be $36 million.

Perry Ellis International Inc. (PERY US) rallied 11 percent to $28.84, the highest price since September 2007. The Miami-based maker of apparel and fragrances agreed to buy Rafaella Apparel Group Inc. for at least $70 million. The acquisition will add 40 cents a share to earnings in the next fiscal year, the company said.

Robbins & Myers Inc. (RBN US) gained 16 percent, the most since June 2008, to $41.18. The maker of fluid management systems forecast second-quarter profit excluding some items of at least 40 cents a share, beating the 35-cent average estimate from analysts in a Bloomberg survey.

Supervalu Inc. (SVU US) had the second-biggest decline in the S&P 500, sliding 5.9 percent to $8.66. The Eden Prairie, Minnesota-based grocer said Steve Jungmann, executive vice President of merchandising, will leave the company. His role will be taken by Janel Haugarth, executive vice president, president and chief operating officer of the company’s Supply Chain Services organization.

Travelers Cos. (TRV US) dropped 2 percent to $53.33, the biggest slide in the Dow average. American International Group Inc. agreed to pay $450 million to the company and six other rivals for shortchanging industry-funded pools that insure injured workers.

Warnaco Group Inc. (WRC US) slumped 4.3 percent, the most since Nov. 10, to $50.40. The owner of swimsuit maker Speedo was cut to “underweight” from “equal-weight” at Morgan Stanley.

Xyratex Ltd. (XRTX US) slumped 14 percent, the most since Sept. 30, to $14.78. The provider of data storage and network technology reported fourth-quarter earnings and sales that trailed analysts’ estimates.