Similarly, pharmaceuticals group Hikma led the fallers after UBS cut its rating on the stock from 'buy' to 'neutral' on valuation grounds, saying that it is 'time to take a pause and breathe' after the stock's recent performance.Chemicals business Synthomer also sunk after JPMorgan Cazenove downgraded its rating on the stock from 'neutral' to 'underweight', saying that the 40% run over the last 12 months is "an opportunity to take profits".Polymer group Victrex said it experienced a better-than-expected second quarter, but warned that currency movements will have a worse impact on results this year and the next, prompting the stock to fall. Evraz shares moved higher on reports Morgan Stanley has upped its rating on the steel giant from 'hold' to 'buy'. FTSE 250 - RisersTullett Prebon (TLPR) 301.30p +2.17%Evraz (EVR) 77.25p +2.05%Computacenter (CCC) 645.00p +1.98%Ashmore Group (ASHM) 347.60p +1.73%888 Holdings (888) 149.00p +1.36%Betfair Group (BET) 1,041.00p +1.36%Lancashire Holdings Limited (LRE) 687.00p +1.33%Vesuvius (VSVS) 450.40p +1.28%Templeton Emerging Markets Inv Trust (TEM) 548.00p +1.11%Rotork (ROR) 2,657.00p +0.95%FTSE 250 - FallersHikma Pharmaceuticals (HIK) 1,552.00p -6.73%Entertainment One Limited (ETO) 308.30p -6.58%Henderson Group (HGG) 250.60p -6.53%Ocado Group (OCDO) 395.50p -6.28%Imagination Technologies Group (IMG) 190.70p -5.87%Synthomer (SYNT) 274.70p -5.80%WH Smith (SMWH) 1,145.00p -5.29%Dixons Retail (DXNS) 45.95p -5.26%Crest Nicholson Holdings (CRST) 379.00p -5.25%Keller Group (KLR) 1,039.00p -5.11%NR