Shares of the following companies are having unusual moves in U.S. trading. Stock symbols are in parentheses, and prices are as of 10:55 a.m. in New York.
Staffing companies advanced after a government report showed employers in the U.S. cut the fewest jobs in November since the recession began and the unemployment rate unexpectedly fell. Robert Half International Inc. (RHI) climbed 9.5 percent to $25.39. Monster Worldwide Inc. (MWW) rallied 11 percent to $16.72. Manpower Inc. (MAN) added 13 percent to $57.86.
American Express Co. (AXP), the biggest credit-card issuer by purchases, rallied 3.3 percent to $20.54 on eased concern that rising unemployment will curb consumer spending.
Akamai Technologies Inc. (AKAM) jumped 7.4 percent to $25.53 and advanced earlier to $25.66, the highest intraday price since July 2008. The largest supplier of software and services to make Web sites load faster was raised to "outperform" from "market perform" at Oppenheimer & Co.
Boeing Co. (BA) rose 2.9 percent to $55.35 and jumped earlier to $55.45, the highest intraday price since Sept. 29. The second-largest defense contractor said demand for helicopters, logistics support and cyber-security services will more than make up for recent losses of Army, missile defense and satellite programs.
Big Lots Inc. (BIG) jumped 18 percent to $27.75 for the biggest gain in the Standard & Poor's 500 Index. The broadline closeout retailer reported profit excluding some items of 27 cents a share in the third quarter, beating the average analyst estimate of 44 percent, according to Bloomberg data.
DuPont Co. (DD) fell the most in the Dow Jones Industrial Average, sliding 4 percent to $33.43. The world's second-biggest seed producer said its Optimum GAT corn fell short of its standards for crop yields and won't be released next year in North America as planned.
General Growth Properties Inc. (GGWPQ) jumped 14 percent to $9.13 and advanced earlier to $9.95, the highest intraday price since October 2008. Brookfield Asset Management Inc. (BAM) and Simon Property Group Inc. (SPG) have purchased part of the mall owner's bank debt and bonds and may make bids for all or part of General Growth, the Wall Street Journal reported, citing people familiar with the matter it didn't identify.
Golden Star Resources Ltd. (GSS) fell 14 percent, the largest intraday decline since April 6, to $3.61. The owner of the Bogoso/Prestea gold mine in Ghana sold 20 million shares at $3.75 each. More stock may dilute the value of existing shares.
Flow International Corp. (FLOW) jumped 20 percent to $2.94 after advancing 33 percent earlier, the most intraday since February 2005. The maker of Dynamic high-pressure water jets for cutting industrial materials reported profit excluding some items of 1 cent a share for the quarter ended Oct. 31, beating the average analyst estimate of a 2 cents loss. LDK Solar Co. (LDK) climbed 9.8 percent to $9.20 after rising earlier to $9.35, the highest intraday price since Sept. 23. The Chinese manufacturer of polysilicon wafers said it ended a contract dispute with Q-Cells SE and reached an agreement to extend sales terms through 2018.
Goodyear Tire & Rubber Co. (GT) rose 6 percent to $14.47 after rising as much as 6.7 percent, the most intraday since Nov. 13. The largest U.S. tiremaker will likely top analysts estimates for fourth-quarter earnings and investors should buy the stock, JPMorgan Chase & Co. said.
Marvell Technology Group Ltd. (MRVL) added 8.6 percent to $17.95 and advanced earlier to $18.20, the highest intraday price since June 2008. The maker of chips for computers and mobile phones reported earnings excluding some items of 35 cents a share for the third quarter, 34 percent more than the average analyst estimate in a Bloomberg survey.
Moody's Corp. (MCO) rose 6.9 percent to $25.17 and increased earlier to $25.76, the highest intraday price since Sept. 16. the company, whose founder John Moody created credit ratings in 1909, was rated "buy" and given a price estimate of $28 in new coverage at Bank of America Corp., which cited the outlook for growth in credit markets.
Smith & Wesson Holding Corp. (SWHC) dropped 17 percent to $4.40 after slumping as much as 18 percent, the most intraday since December 2008. The gun maker forecast third-quarter sales of $95 million at most, trailing the average analyst estimate of $104.5 million, according to Bloomberg data.
Southwest Airlines Co. (LUV) rose 6.5 percent to $10.13 after jumping as much as 7.1 percent, the most intraday since April 28. The biggest low-fare airline said it flew 5.9 billion revenue passenger miles in November, a 12 percent increase from a year earlier.
Steris Corp. (STE) slumped 20 percent to $26.72 and tumbled 23 percent earlier, the most intraday since April 1999. The company's STERIS System 1 Processor, a sterilization product for use in hospitals, has caused injuries and should be replaced "as soon as possible," the U.S. Food and Drug Administration said on its Web site.
Take-Two Interactive Software Inc. (TTWO) plunged 31 percent to $7.50 and tumbled 36 percent earlier, the most intraday since December 2001. The maker of the "Grand Theft Auto" video games forecast a loss of at least 40 cents a share in the fiscal first quarter. That's wider than the average 26- cent loss estimated by analysts in a Bloomberg survey.
Western Gas Partners LP (WES) dropped 4.6 percent to $18.10 and sank 5.1 percent earlier, the most intraday since Nov. 2. The natural-gas pipeline owner and processor sold 6 million common units at $18.20 each. More units may dilute the value of existing equity.