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.
Operators of U.S. nursing homes rallied after Medicare said it would increase payments to the companies by 1.9 percent in fiscal 2013. Kindred Healthcare Inc. (KND US) surged 19 percent to $9.86. Skilled Healthcare Group Inc. (SKH US) added 5.6 percent to $7.49. Select Medical Holdings Corp. (SEM US) jumped 12 percent to $8.82.
Accretive Health Inc. (AH US) slumped 42 percent, the most since its May 2010 initial public offering, to $10.75. The collection agency is being sued by Minnesota Attorney General Lori Swanson for violations of U.S. and state patient-privacy and debt-collection laws.
Aflac Inc. (AFL US) rose 7.8 percent, the most since Oct. 27, to $45.26. The world’s biggest seller of supplemental health insurance said first-quarter profit doubled as investment results improved.
Apple Inc. (AAPL US) surged 8.9 percent, the most since November 2008, to $610. The world’s largest company by market value posted profit that almost doubled last quarter, reflecting robust demand for the iPhone in China as well as purchases of a new version of the iPad tablet.
Apple’s suppliers gained. Cirrus Logic Inc. (CRUS US) increased 11 percent to $23.09. Broadcom Corp. (BRCM US) advanced 6.1 percent to $36.51.
Boeing Co. (BA US) rose the most in the Dow Jones Industrial Average, rallying 5.3 percent to $77.08. The world’s biggest aerospace company reported first-quarter profit that beat analysts’ estimates as it delivered more commercial jets while pushing production to record levels.
Caterpillar Inc. (CAT US) fell 4.6 percent to $103.44, the biggest drop in the Dow Jones Industrial Average. The largest maker of construction and mining equipment reported a gain in first-quarter revenue that missed analysts’ estimates as sales of construction equipment fell in China and Brazil.
C.H. Robinson Worldwide Inc. (CHRW US) sank 7.5 percent, the biggest drop in the Standard and Poor’s 500 Index, to $60.91. The transportation-services company reported first-quarter sales that missed analysts’ estimates.
Cray Inc. (CRAY US) rallied 21 percent, the most since February 2011, to $8.51. The Seattle-based company agreed to sell technology used to connect server chips to Intel Corp. (INTC US) for $140 million.
Corning Inc. (GLW US) advanced 7.1 percent, the most since Oct. 27, to $14.30. The largest maker of glass for flat-panel television sets reported first-quarter earnings excluding some items of 30 cents a share, exceeding the average analyst estimate of 28 cents.
Dana Holding Corp. (DAN US) increased 9.4 percent, the most since Aug. 11. to $15.21. The maker of vehicle axles and other driveline components reported first-quarter earnings excluding some items of 44 cents a share, beating the average analyst estimate of 41 cents.
Diebold Inc. (DBD US) rose 5.9 percent to $40.68, the highest price since November 2007. The maker of automated bank-teller machines boosted its full-year forecast after first-quarter profit more than doubled the average analysts estimate.
Edwards Lifesciences Corp. (EW US) gained 12 percent, the most since September 2010, to $81.84. The largest maker of artificial heart valves worldwide said first-quarter sales rose 14 percent as U.S. doctors began implanting its Sapien device.
GeoResources Inc. (GEOI US) rose 19 percent to $36.52, the highest price since at least 1989. The oil and gas producer agreed to be bought by Halcon Resources Corp. (HK US) in a cash-and-stock takeover that values the company at $972 million. Halcon climbed 9.7 percent to $10.20.
GNC Holdings Inc. (GNC US) climbed 12 percent to $39.89, the highest price since it went public a year ago. The operator of health and wellness stores reported first-quarter earnings excluding some items of 60 cents a share, exceeding the average analyst estimate of 53 cents.
Hess Corp. (HES US) fell 7 percent, the most since Sept. 22, to $51.18. The energy company posted first-quarter profit excluding some items of $1.49 a share, trailing the average analyst estimate of $1.53, according to data compiled by Bloomberg.
Iconix Brand Group Inc. (ICON US) fell 15 percent, the most since September 2009, to $14.53. The company that licenses brands such as Joe Boxer and London Fog to retailers slashed its full-year earnings forecast, citing slowing demand for men’s brands.
Inphi Corp. (IPHI US) slumped 28 percent, the most since Aug. 24, to $9.80. The semiconductor company was cut to neutral from overweight at Piper Jaffray Cos.
Nabors Industries Ltd. (NBR US) climbed 6.3 percent, the most since Feb. 22, to $16.96. The oil and natural gas driller reported first-quarter earnings that beat the average analyst estimate by 30 percent, the most since at least 2005, according to Bloomberg data.
Panera Bread Co. (PNRA US) climbed 6.6 percent, the most since Oct. 26, to $158.07. The bakery chain based in St. Louis reported first-quarter earnings of $1.40 a share, beating the $1.34 projected by analysts on average.
RF Micro Devices Inc. (RFMD US) increased 8.8 percent, the most since Nov. 30, to $4.32. The maker of chips and radio systems for mobile phones reported fourth-quarter revenue of $187.9 million, exceeding the average analyst estimate of $185.2 million.
Robert Half International Inc. (RHI US) jumped 5.7 percent, the most since Nov. 30, to $30.49. The staffing company reported first-quarter profit of 34 cents a share, beating the average analyst estimate by 22 percent, according to data compiled by Bloomberg.
Unisys Corp. (UIS US) climbed 20 percent, the most since Oct. 25, to $19.70. The Pennsylvania producer of mainframes and computer services reported first-quarter profit that beat analysts’ estimates by the most since 2008, according to data compiled by Bloomberg.
USANA Health Sciences Inc. (USNA US) rose 11 percent, the most since July 2009, to $41. The vitamin maker lifted its profit forecast for 2012 to at least $3.60 a share from an earlier projection of no more than $3.45, topping the average analyst estimate of $3.44.
Zipcar Inc. (ZIP US) dropped 11 percent to $12.33 the lowest price since it went public in April 2011. The company that rents cars by the hour or day said second-quarter revenue wouldn’t exceed the average analyst forecast.