Trendy fashion retailer SuperGroup is surging Wednesday following its best ever Christmas, almost doubling retail sales during the nine weeks to 2 January. Retail sales grew 93.6% during the period to £51.7m and wholesale sales were up 77.8% at £13.4m, making a 90.1% increase in total sales to £65.1m. Business over the internet also continued to swell, up 243%. Judging by the share price reaction, the takeover of troubled fund manager Gartmore by rival money manager Henderson Group is a win-win situation."Gartmore is a natural fit with Henderson, with a highly complementary strategy and stable of products," claimed Henderson chief executive officer Andrew Formica.Price comparison website Moneysupermarket.com is also higher after saying that trading in the fourth quarter has continued to be strong and it expects full year earnings to be at the upper end of market expectations.Internet and catalogue home shopping company N Brown has seen its share price fall despite announcing an increase of 4.6% in group revenue in the 19 weeks to 8 January. Brown says trading was encouraging from late October to mid-December "but the extreme weather conditions eventually affected customers who were concerned whether their Christmas orders would be delivered on time."FTSE 250 - RisersSupergroup (SGP) 1,372.00p +17.87%Gartmore Group Ltd. (GRT) 101.20p +11.70%Henderson Group (HGG) 152.00p +9.99%Moneysupermarket.com Group (MONY) 85.00p +9.89%Fenner (FENR) 389.70p +9.87%Savills (SVS) 350.00p +7.69%Restaurant Group (RTN) 293.60p +6.92%Croda International (CRDA) 1,605.00p +4.09%Ocado Group (OCDO) 190.00p +4.05%Elementis (ELM) 140.20p +3.85%FTSE 250 - FallersExillon Energy (EXI) 375.00p -3.85%Devro (DVO) 241.50p -3.82%Cookson Group (CKSN) 649.50p -3.71%Sports Direct International (SPD) 168.80p -3.38%Cranswick (CWK) 857.00p -2.83%Dunelm Group (DNLM) 483.00p -2.82%Ashtead Group (AHT) 171.30p -2.78%Soco International (SIA) 351.00p -2.77%Amlin (AML) 382.20p -2.72%Forth Ports (FPT) 1,368.00p -2.70%