A123 Systems, Baidu, Groupon, TripAdvisor: 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.

Base metal producers rallied as copper, aluminum, zinc and tin rose on speculation stronger gauges of manufacturing may signal increased demand for industrial metals.

U.S. Steel Corp. (X US) advanced 6.4 percent to $28.16. Alcoa Inc. (AA US) gained 6.7 percent, the most in the Dow Jones Industrial Average, to $9.23. Freeport-McMoRan Copper & Gold Inc. (FCX US) rose 7.4 percent to $39.50.

Coal producers advanced as analysts at UBS AG, Dahlman, Brean Murray, and Wunderlich said the implementation delay of the Cross-State Air Pollution Rule by the federal court Dec. 30 may benefit eastern coals.

Peabody Energy Corp. (BTU US) gained 9.5 percent, the second-biggest increase in the Standard & Poor’s 500 Index, to $36.27. Alpha Natural Resources Inc. (ANR US) rose 8 percent to $22.07.

A123 Systems Inc. (AONE US) jumped 22 percent, the most since Oct. 12, to $1.96. Fisker Automotive Inc. said most plug-in electric sports cars using packs from the maker of lithium-ion batteries for rechargeable vehicles already have been fixed.

Baidu Inc. (BIDU US) climbed 6.7 percent, the most since Oct. 24, to $124.29. China’s biggest Internet company by market value may boost acquisitions this year, Mizuho Securities analyst Muzhi Li said in a note.

Cisco Systems Inc. (CSCO US) increased 3.4 percent to $18.63. The world’s biggest maker of networking equipment was raised to “overweight” from “neutral” at JPMorgan Chase & Co.

Devon Energy Corp. (DVN US) rose 6.6 percent, the most since May 2009, to $66.11. The biggest independent oil and natural-gas producer in the U.S. said China Petroleum & Chemical Corp.’s Sinopec International Petroleum Exploration & Production unit agreed to buy a one-third stake in five of Devon’s exploratory oil projects covering 1.2 million acres in the U.S. for $900 million.

Groupon Inc. (GRPN US) fell 6.6 percent, the most since Nov. 28, to $19.27. The largest Internet daily-deal fell after a survey from Susquehanna Financial Group indicated that about half of merchants that have offered a daily deal have no plans to do so again in the next six months.

MBIA Inc. (MBI US) gained 8.1 percent, the most since Nov. 30, to $12.53. The financial-guarantee insurer won a summary judgment ruling against Bank of America Corp.’s (BAC US) Countrywide unit, according to a court filing.

Micron Technology Inc. (MU US) advanced 7.4 percent to $6.76, the highest price since Sept. 20. The largest U.S. maker of computer-memory chips was raised to “overweight” from “equal weight” at Barclays Capital by equity analyst CJ Muse, with a price estimate of $9 per share.

Rambus Inc. (RMBS US) rose 7.4 percent to $8.11, the highest price since Dec. 23. The designer of high-speed memory chips said it sees preliminary fourth-quarter revenue of $83 million, above the average analyst estimate of $69 million.

Research In Motion Ltd. (RIMM US) gained 7 percent to $15.51, the highest price since Dec. 12. The maker of the BlackBerry smartphone said the company may name an independent chairman to appease investors wanting to see a leadership change. Former Royal Bank of Canada Chief Operating Officer Barbara Stymiest, a RIM director, may be the leading candidate for the job, the National Post reported today, citing unidentified sources familiar with the situation.

Telestone Technologies Corp. (TSTC US) sank 15 percent to $3.52, the lowest price since June 2009. The Chinese maker of wireless gear said its 2011 revenue would be 15 percent to 20 percent lower than last year, compared with previous guidance of a 30 percent increase.

Terex Corp. (TEX US) rallied 6.8 percent to $14.43, the highest price since Dec. 12. The Westport, Connecticut-based construction equipment company was raised to “overweight” from “neutral” at JPMorgan Chase & Co.

TripAdvisor Inc. (TRIP US) rose 5.6 percent to $26.63, the highest price since Dec. 21. The world’s largest travel site was raised to “buy” from “underperform” at Bank of America, saying fourth-quarter earnings should improve transparency.

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