Chip designer Imagination Technologies, saw shares jump around 10% today, extending gains made yesterday after it was reported that its MIPS technology had been included in a new security camera chip by MediaTek, one of rival ARM's biggest customers. The stock has now gained 14% in the last two days.Healthcare stocks such as Al Noor Hospitals and UDG Healthcare rose on the back of yet more M&A speculation in the sector, this time surrounding medical devices group Smith & Nephew.UK residential property developer Bellway inched higher after saying that demand for new homes in its third quarter remained robust, buoyed by growing consumer confidence and a strong supply of mortgages. Sector peer Berkeley rose in sympathy.Satellite operator Inmarsat was also in demand as it announced plans to provide the first Europe-wide in-flight broadband internet service, with the launch of a new dedicated satellite in late 2016 and completion of an air-to-ground network.Heading the other way were retailers after a surprise profit warning from high-growth online fashion group ASOS dampened sentiment in the sector. N Brown, the home shopping group which owns several brands such as Simply Be and Jacamo, was among the worst fallers on the FTSE 250.FTSE 250 - RisersImagination Technologies Group (IMG) 258.00p +9.60%AL Noor Hospitals Group (ANH) 1,050.00p +4.37%Rathbone Brothers (RAT) 2,135.00p +3.14%Petra Diamonds Ltd.(DI) (PDL) 167.40p +2.14%Man Group (EMG) 101.00p +2.12%Inmarsat (ISAT) 733.50p +2.09%Ferrexpo (FXPO) 136.90p +2.01%UDG Healthcare Public Limited Company (UDG) 358.80p +1.93%Berkeley Group Holdings (The) (BKG) 2,306.00p +1.90%Evraz (EVR) 97.90p +1.77%FTSE 250 - FallersXaar (XAR) 790.50p -3.30%Brown (N.) Group (BWNG) 453.80p -3.28%Cairn Energy (CNE) 200.00p -2.30%Micro Focus International (MCRO) 821.50p -2.09%Partnership Assurance Group (PA.) 123.50p -1.91%Northgate (NTG) 515.00p -1.90%ITE Group (ITE) 228.40p -1.89%Redrow (RDW) 262.20p -1.72%Halma (HLMA) 595.00p -1.65%Home Retail Group (HOME) 185.90p -1.64%BC