Soco International shares started trading without the entitlement to its 40p dividend. SOCO announced on Wednesday that the drill stem tests thus far on the TGT-10XST1 well exploration well on the H5 fault block of the Te Giac Trang ("TGT") field have exceeded all pre-test expectations. Ladbrokes slumped after warning that 2013 profits for its digital operations would come in a long way below current market forecasts. It said it expected 2013 Digital operating profits to be between £10m and £14m compared with a market consensus of about £27.5m. Numis and Canaccord Geunity downgraded their ratings for the stock this morning.Tour operator Thomas Cook also fell sharply after reporting a decline in bookings in the UK over summer and flat sales in Europe. In a trading update ahead of the company's full-year 2013 results in November, the group said UK bookings were down 3% on last year with a capacity reduction of 2.5%. Meanwhile, iron ore producer Ferrexpo was a high riser after Macquarie upgraded its rating on the stock to 'neutral' and lifted its target price from 155p to 180p.FTSE 250 - RisersMan Group (EMG) 87.25p +4.43%AZ Electronic Materials SA (DI) (AZEM) 309.10p +3.55%Ferrexpo (FXPO) 183.40p +3.38%Polymetal International (POLY) 683.50p +3.25%Domino's Pizza Group (DOM) 592.50p +3.22%Tullett Prebon (TLPR) 355.10p +3.05%Centamin (DI) (CEY) 46.90p +2.96%IP Group (IPO) 143.80p +2.71%Workspace Group (WKP) 444.60p +2.58%Diploma (DPLM) 646.50p +2.21%FTSE 250 - FallersSoco International (SIA) 393.00p -8.60%Thomas Cook Group (TCG) 145.10p -6.75%Ladbrokes (LAD) 178.00p -5.37%Mitchells & Butlers (MAB) 413.50p -3.55%Playtech (PTEC) 720.50p -3.09%Dunelm Group (DNLM) 949.50p -2.67%Barratt Developments (BDEV) 310.00p -2.64%Kazakhmys (KAZ) 285.80p -2.42%ICAP (IAP) 379.50p -2.29%Taylor Wimpey (TW.) 100.20p -2.24%NR