Mixed reactions to corporate earnings provided some sharp swings in share prices both ways on Thursday, with Rolls-Royce, Shire and Reed Elsevier rising strongly and Capita, Unilever, BT Group and Johnson Matthey falling into the red. Rolls-Royce Holdings jumped after reporting a 34% jump in pre-tax profits to £840m for the first half as the engine maker secured more orders. Pharmaceuticals giant Shire surged this afternoon after it reported better-than-anticipated second-quarter results and said it now expected to deliver double-digit earnings growth this year, ahead of previous forecasts.Reed Elsevier also impressed with strong growth from its key academic publishing and legal solutions businesses as margins continued their upward trend.In contrast, outsourcing giant Capita was a heavy faller after it saw margins shrink in the first half despite the booming market for its services. Consumer products giant Unilever also fell after admitting in its interim results that the economic environment remains tough and growth in the emerging markets is starting to slow.Telecoms titan BT scored a solid rise in underlying profit but recorded a slight pullback in revenue in the first quarter, causing the stock to take a hit today.Chemicals firm Johnson Matthey was under the weather after saying that its performance in the second quarter will be lower than the first due to planned summer shutdowns in the auto industry.Chip designer ARM Holdings however was the standout faller today, extending losses made yesterday after its interim results. Analysts at Sanford C Bernstein said today that the stock's valuation could fall in the second half.Meanwhile, mining stocks were dampened by falling metals prices, with Fresnillo, Anglo American and Glencore Xstrata among the worst performers.FTSE 100 - RisersRolls-Royce Holdings (RR.) 1,227.00p +3.98%Shire Plc (SHP) 2,299.00p +3.70%Reed Elsevier (REL) 830.00p +3.62%Severn Trent (SVT) 1,761.00p +1.09%United Utilities Group (UU.) 718.00p +1.06%Tullow Oil (TLW) 1,030.00p +0.88%GlaxoSmithKline (GSK) 1,695.00p +0.83%Standard Life (SL.) 379.90p +0.61%Babcock International Group (BAB) 1,186.00p +0.51%Admiral Group (ADM) 1,398.00p +0.43%FTSE 100 - FallersARM Holdings (ARM) 847.50p -4.61%GKN (GKN) 326.20p -4.37%Fresnillo (FRES) 1,025.00p -4.12%SABMiller (SAB) 3,111.50p -3.97%Capita (CPI) 998.00p -3.76%Anglo American (AAL) 1,391.00p -3.27%Hargreaves Lansdown (HL.) 969.00p -2.71%Weir Group (WEIR) 2,078.00p -2.67%British Land Co (BLND) 597.00p -2.37%Glencore Xstrata (GLEN) 280.75p -2.26%BC