Iron ore group Ferrexpo was under pressure today after being cut from 'buy' to 'neutral' by UBS "due to the elevated political risk in the Ukraine".Diploma revealed improved first-quarter revenue but fell after it cautioned that overseas progress was hurt by the strengthening pound. The technical products supplier and services provider said revenues in the first quarter ended December 31st rose 4% from the comparable period last year. On an underlying basis, after adjusting for the impact of currencies, revenues increased by 6%.Meanwhile, improved investor confidence and a strong performance from its funds saw Jupiter Fund Management accelerate growth in assets under management in the fourth quarter, pushing the stock firmly higher. During the quarter the group's mutual funds increased in market value by £966m and enjoyed £458m of net fund inflows, which together were the main drivers of AuM growth of 6% to £31.66bn. Imagination Technology shares climbed after Apple's Tim Cook said he was "incredibly optimistic" about the US company's deal with China Mobile for its iPhones, certain parts of which are Imagination Tech designs. FTSE 250 - RisersFoxtons Group (FOXT) 355.10p +5.06%Imagination Technologies Group (IMG) 190.70p +4.55%Bwin.party Digital Entertainment (BPTY) 118.80p +3.66%Ladbrokes (LAD) 170.50p +3.21%Carphone Warehouse Group (CPW) 277.40p +3.20%Spirent Communications (SPT) 92.90p +2.37%Go-Ahead Group (GOG) 1,940.00p +2.37%Jupiter Fund Management (JUP) 389.30p +2.34%Scottish Mortgage Inv Trust (SMT) 1,099.00p +2.33%Home Retail Group (HOME) 199.60p +2.31%FTSE 250 - FallersFerrexpo (FXPO) 169.60p -4.02%Keller Group (KLR) 1,226.00p -3.39%888 Holdings (888) 158.20p -3.18%Polymetal International (POLY) 514.00p -3.02%Debenhams (DEB) 82.90p -2.81%Lonmin (LMI) 299.90p -2.79%CSR (CSR) 677.50p -2.52%Daejan Holdings (DJAN) 4,600.00p -1.92%Micro Focus International (MCRO) 747.50p -1.84%Diploma (DPLM) 697.00p -1.83%NR