Iron ore producer Ferrexpo and oil company JKX have benefited from an increase in commodity prices.They're closely followed by recruitment firm Hays, which has returned to year on year growth for the first time in two years.Dixons group DSG International is wanted after it emerged that UBS Global Asset Management increased its stake in the electronics retailer by 34m shares last week to 7%.Social housing firm Connaught fell further on news it is looking for a new chief executive after current boss Mark Tincknell stood down to recover from recent health issues. Finance director Stephen Hill has also decided his time is up at the company and will be leaving at the end of October.FTSE 250 - RisersFerrexpo (FXPO) 268.30p +5.67%JKX Oil & Gas (JKX) 275.90p +5.23%Rank Group (RNK) 103.90p +5.22%Hays (HAS) 95.25p +5.19%Telecity Group (TCY) 396.50p +5.17%Senior (SNR) 129.70p +5.02%Computacenter (CCC) 283.30p +4.93%Grainger (GRI) 119.60p +4.91%DSG International (DSGI) 27.21p +4.86%Imagination Technologies (IMG) 305.50p +4.66%FTSE 250 - FallersConnaught (CNT) 112.00p -5.08%Promethean World (PRW) 169.90p -4.01%Game Group (GMG) 61.45p -2.46%Gartmore Group (GRT) 103.30p -2.46%Mothercare (MTC) 551.50p -2.30%Eaga (EAGA) 114.50p -1.55%Greggs (GRG) 463.50p -1.45%Brit Insurance Holdings NV (BRE) 912.00p -1.41%Provident Financial (PFG) 848.00p -1.22%PZ Cussons (PZC) 347.00p -1.14%