Shares in QinetiQ rocketed as the high-tech defence group shrugged off the squeeze in defence spending to lift underlying interim profits and promise a return to dividends at the year-end.Bike and car parts retailer Halfords pedals forward after it reported a healthy rise in sales and profits in the 26 weeks to 1 October, but trading remains tough, with like-for-like sales under pressure.It's a tale of two Melroses today, with industrial products group Melrose going well after saying revenue recovery has continued, but Melrose Resources falling back after the oil group's latest update failed to impress investors.Today's heaviest faller is ground preparation specialist Keller, which said it anticipates full year results to be around the bottom end of market expectations as intense competition continues to bite.FTSE 250 - RisersQinetiQ Group (QQ.) 110.90p +12.02%Regus (RGU) 81.60p +5.84%Imagination Technologies Group (IMG) 317.60p +4.65%CPP Group (CPP) 268.40p +4.64%Melrose (MRO) 287.60p +4.62%London Stock Exchange Group (LSE) 749.00p +4.46%PartyGaming (PRTY) 229.10p +4.14%Halfords Group (HFD) 428.50p +4.13%JD Sports Fashion (JD.) 812.00p +4.10%JPMorgan Russian Securities (JRS) 628.50p +4.06%FTSE 250 - FallersKeller Group (KLR) 548.00p -7.90%Melrose Resources (MRS) 240.00p -4.91%Babcock International Group (BAB) 530.00p -4.50%Mitie Group (MTO) 197.60p -3.04%Heritage Oil (HOIL) 365.10p -2.85%Micro Focus International Plc (MCRO) 323.10p -2.39%Amlin (AML) 382.60p -2.27%Hiscox Ltd. (HSX) 355.30p -2.15%International Public Partnerships Ltd. (INPP) 111.30p -1.50%TR Property Inv Trust Sigma Shares (TRYS) 73.30p -1.35%