Misys was the biggest riser after its largest shareholder ValueAct Capital Master Fund has teamed up with CVC Capital Partners in preparation to make a joint cash offer for the financial software provider. Heritage Oil was a big faller after it was hit by delays to its operations in the Kurdistan Region of Iraq, as it has been forced to create a sidetrack well on its Miran West-3 well.Shares in Dunelm plunged after Will Adderley, Executive Deputy Chairman and the son of the founder of the company, announced plans to cash in a big chunk of his shares in the bedding and curtains retailer. Also heading lower was Amlin after an 'exceptionally challenging year' for insurance and reinsurance underwriter. In the year ended December 31st which saw earthquakes in New Zealand and Japan, tornadoes in the US and floods in Australia, Denmark and Thailand, the group made a loss before tax of £193.8m, compared with a profit of £259.2m the year before. FTSE 250 - RisersMisys (MSY) 334.40p +5.79%Allied Gold Mining (ALD) 113.80p +4.21%Chemring Group (CHG) 425.30p +3.66%JD Wetherspoon (JDW) 412.30p +2.72%Brewin Dolphin Holdings (BRW) 161.70p +2.67%Elementis (ELM) 180.20p +2.27%International Personal Finance (IPF) 251.30p +1.37%Savills (SVS) 369.40p +1.21%Atkins (WS) (ATK) 777.00p +1.17%Stobart Group Ltd. (STOB) 129.40p +1.09%FTSE 250 - FallersFerrexpo (FXPO) 303.00p -5.99%Exillon Energy (EXI) 225.00p -4.66%Amlin (AML) 336.00p -4.41%Heritage Oil (HOIL) 167.80p -4.39%Kenmare Resources (KMR) 55.00p -4.35%Taylor Wimpey (TW.) 47.53p -4.25%Dunelm Group (DNLM) 487.00p -4.23%Petropavlovsk (POG) 665.00p -4.04%Kesa Electricals (KESA) 72.60p -3.97%New World Resources A Shares (NWR) 510.50p -3.68%NR