Housebuilder Persimmon leads the risers after saying it has seen both volume and revenues improve recently and expects that trend to continue against the weak conditions experienced throughout the second half of 2008.Fellow housebuilders Barratt and Bovis, due to report on Thursday and Friday respectively, are up in sympathy.Home shopping company N Brown said in the 18 weeks to July 2009 turnover increased by 5.1%, in line with its plan. The shares are lower.An inline trading update has also failed to help Dechra Pharm. The pharmaceutical firm focused on the veterinary sector said trading for the year to June is in line with management's expectations.FTSE 250 - RisersPersimmon (PSN) 385.25p +6.06%SThree (STHR) 170.00p +5.43%Ferrexpo (FXPO) 131.00p +5.01%Bovis Homes Group (BVS) 408.75p +4.87%Barratt Developments (BDEV) 156.25p +4.69%Tomkins (TOMK) 157.00p +4.67%DS Smith (SMDS) 63.50p +4.10%Bellway (BWY) 652.50p +4.07%Euromoney Institutional Investor (ERM) 233.75p +3.89%Aberdeen Asset Management (ADN) 128.75p +3.83%FTSE 250 - FallersMorgan Sindall (MGNS) 623.50p -5.53%Brown (N.) Group (BWNG) 209.00p -5.00%Domino Printing (DNO) 237.50p -4.62%GKN (GKN) 79.75p -4.52%Dunelm (DNLM) 208.75p -4.24%Mitie Group (MTO) 209.75p -4.11%PayPoint (PAY) 489.00p -3.74%Hunting (HTG) 387.50p -3.73%Dechra Pharmaceuticals (DPH) 430.00p -3.70%Marston's (MARS) 88.50p -3.65%