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.
Augusta Resource Corp. (AZC US) climbed 9.2 percent, the most since July 30, to $2.26. The mining company said HudBay Minerals Inc. (HBM CN) agreed to buy C$30 million ($28.3 million) of shares and warrants, boosting its stake to as much as 13.6 percent.
Daktronics Inc. (DAKT US) jumped 17 percent, the most since November 2008, to $9.17. The maker of Times Square video displays and other electronic billboards said that it earned 6 cents a share in the fiscal first quarter. Analysts, on average, estimated a loss of 5 cents, according to a Bloomberg survey.
Dell Inc. (DELL US) declined 3 percent to $11.59, the lowest price since May 2009. The world’s third-largest personal-computer maker is readying a sweetened offer for data-storage provider 3Par Inc. after its earlier bid was bested by a $1.6 billion proposal from Hewlett-Packard Co., according to a person familiar with the matter.
3Par (PAR US) gained 3.6 percent to $27.04.
Diamond Management & Technology Consultants Inc. (DTPI US) rose 31 percent, the most since September 2008, to $12.54. The provider of computer-consulting services signed a merger agreement with PricewaterhouseCoopers LLP for Pricewaterhouse to buy all outstanding Diamond shares for $12.50 each, valuing Diamond at $378 million, the companies said.
Freeport-McMoRan Copper & Gold Inc. (FCX US) declined 4.7 percent, the most since July 16, to $67.05. The world’s second-largest copper producer was cut to “neutral” from “overweight” at HSBC Holdings Plc.
Massey Energy Co. (MEE US) lost 4.4 percent to $30.16, the lowest price since July 28. The owner of the West Virginia mine where 29 people died in April said the U.S. Mine Safety and Health Administration cited it for storing explosives in an improper place.
Medtronic Inc. (MDT US) fell the most in the Standard & Poor’s 500 Index, slumping 11 percent to $31.21. The world’s largest maker of heart devices lowered its fiscal-year 2011 adjusted earnings forecast to $3.45 to $3.53 a share from $3.54 to $3.64 a share.
Other medical device makers also slipped. Intuitive Surgical Inc. (ISRG US) retreated 4.9 percent to $269.12. Stryker Corp. (SYK US) dropped 6.4 percent to $43.20. Boston Scientific Corp. (BSX US) lost 2.5 percent to $5.49. Zimmer Holdings Inc. (ZMH US) fell 4.9 percent to percent to $47.97. St. Jude Medical Inc. (STJ US) declined 3.4 percent to $35.42.
RF Micro Devices Inc. (RFMD US) climbed 8.9 percent, the most since Sept. 10, to $5.12. The U.S. maker of chips and radio systems for mobile phones is seeing “modest improvement” in Chinese handset shipments, Sterne Agee & Leach analyst Vijay Rakesh wrote in a note today. Rakesh reiterated a recommendation to buy the shares.
SanDisk Corp. (SNDK US) fell 6 percent to $38.27, the lowest price since May 7. The biggest maker of flash-memory cards declined after Pacific Crest Securities Inc. said its share price was “unwarranted,” given that NAND memory prices may plunge in coming months.
SunPower Corp. (SPWRA US) fell 4.1 percent to $10.11, the lowest price since at least November 2005. The second-biggest U.S. maker of solar-power modules, declined after a report showing sales of the nation’s existing homes dropped twice as much as forecast.
Other solar companies fell. JA Solar Holdings Co. (JASO US) lost 3.9 percent to $5.49. Suntech Power Holdings Co. (STP US) declined 5.4 percent to $7.82.