Plant hire group Ashtead saw its share price soar 19% after announcing that it has raised full-year guidance after a strong first quarter performance. Underlying revenue was up 12%, or 21% on a constant exchange rates (CER) basis in the three months to the end of July from a year earlier, while pre-tax profit was up 136% on a like-for-like basis. Shares in Kesa Electricals, along with a number of other retailers, dropped after broker Citigroup lowered its rating on the UK retail sector to "neutral" from "overweight." FTSE 250 - RisersAshtead Group (AHT) 133.20p +18.93%Betfair Group (BET) 660.50p +5.18%Soco International (SIA) 325.50p +4.93%Kenmare Resources (KMR) 41.73p +4.19%Fenner (FENR) 346.90p +3.92%Telecity Group (TCY) 558.00p +2.48%Hiscox Ltd. (HSX) 351.20p +2.27%African Barrick Gold (ABG) 587.50p +2.26%Thomas Cook Group (TCG) 39.32p +2.24%Hochschild Mining (HOC) 513.00p +1.99%FTSE 250 - FallersExillon Energy (EXI) 220.20p -8.71%AZ Electronic Materials SA (WI) (AZEM) 218.20p -4.72%Kesa Electricals (KESA) 96.70p -4.54%Premier Foods (PFD) 12.25p -4.45%Halfords Group (HFD) 279.50p -4.31%Senior (SNR) 141.60p -3.48%Inchcape (INCH) 286.60p -3.37%Barratt Developments (BDEV) 75.85p -3.31%Ashmore Group (ASHM) 391.30p -3.24%Carpetright (CPR) 515.50p -3.10%NR