After its recent dramatic falls in its share price, Premier Foods continued to build on the 28% gains it has made over the past month. Spread betting pioneer IG Group was also on the up after it saw a high level of client activity in the second quarter of its financial year, continuing the trend seen in the first.As a result, the group currently expects to achieve revenues in excess of £193.0m for the first half, compared to £156.7m in the corresponding period for the prior year, a 23% gain. Evolution Securities raised its target on the stock from 530p to 550p, and retained its buy rating. Shares in oil exploration firm Enquest jumped this morning after it upped production guidance after deciding to develop two new fields.Enquest said it would begin an $850m development of its Alma and Galia fields, subject to anticipated regulatory approvals. Thomas Cook was the biggest faller, with investors likely to be put off the sector on news that AMR Corp, parent company of American Airlines, has filed for bankruptcy protection. RIT Capital, the investment trust, saw its share price drop after reports that it has been battered by "the most torrid markets of my lifetime" says Jacob Rothschild, the chairman of the firm.In the half-yearly results statement he describes Europe as the 'lead violinist in a discordant band'. FTSE 250 - RisersPremier Foods (PFD) 5.41p +13.79%EnQuest (ENQ) 101.50p +11.54%IG Group Holdings (IGG) 473.30p +9.11%Euromoney Institutional Investor (ERM) 674.50p +6.89%Renishaw (RSW) 884.00p +6.83%COLT Group SA (COLT) 92.00p +6.67%Northgate (NTG) 236.40p +6.49%Home Retail Group (HOME) 84.45p +6.23%Heritage Oil (HOIL) 177.20p +6.17%Imagination Technologies Group (IMG) 458.40p +5.40%FTSE 250 - FallersThomas Cook Group (TCG) 19.25p -11.41%Kenmare Resources (KMR) 32.36p -5.19%Ferrexpo (FXPO) 281.70p -3.36%RIT Capital Partners (RCP) 1,267.00p -2.91%Dignity (DTY) 786.50p -2.18%Henderson Group (HGG) 109.20p -2.06%JPMorgan Indian Inv Trust (JII) 333.00p -1.86%Bwin.party Digital Entertainment (BPTY) 134.20p -1.61%Moneysupermarket.com Group (MONY) 102.50p -1.54%International Personal Finance (IPF) 184.50p -1.44%NR