Iron pellet producer Ferrexpo was the high riser on the FTSE 250 on Wednesday with shares up over 10 per cent after a solid first-half report.Revenues were up 6.0% year-on-year at $775m as strong sales demand offset lower market pricing. Analyst Louise Collinge from Investec said that underlying earnings of $244m, up 1.0%, came in slightly ahead of estimates."We believe that Ferrexpo's interim results will be well received by the market, as the group has demonstrated H1 production and costs which put it on track to achieve its full year targets," she said. Heading the other way was pubs group Greene King after going ex-dividend, meaning that from today new investors won't be able to get their hands on the firm's latest payout.Other stocks that went ex-div today include Dialight, Domino's Pizza, Hiscox, Jupiter, Pennon, RPC, Synergy Health, Spirent Communications and St Modwen Properties.United Drug, the provider of services to healthcare manufacturers and pharmacies, was lower despite saying that trading in the third quarter has been "strong". The company reiterated its guidance for 5-8% growth in adjusted diluted earnings per share this year.FTSE 250 - RisersFerrexpo (FXPO) 180.40p +10.40%Perform Group (PER) 541.50p +2.75%Imagination Technologies Group (IMG) 243.50p +2.74%Polymetal International (POLY) 653.50p +2.59%Bumi (BUMI) 218.90p +2.10%Cranswick (CWK) 1,162.00p +1.93%Paragon Group Of Companies (PAG) 342.80p +1.54%COLT Group SA (COLT) 102.80p +1.38%Supergroup (SGP) 1,101.00p +1.29%Renishaw (RSW) 1,596.00p +1.27%FTSE 250 - FallersGreene King (GNK) 846.00p -5.74%Homeserve (HSV) 252.00p -4.04%Savills (SVS) 638.50p -3.91%United Drug (UDG) 344.40p -3.77%Lancashire Holdings (LRE) 775.50p -3.72%Alent (ALNT) 352.70p -3.53%Thomas Cook Group (TCG) 164.60p -3.52%Dunelm Group (DNLM) 987.00p -2.95%Greggs (GRG) 391.50p -2.68%Micro Focus International (MCRO) 790.00p -2.65%BC