Bookmaker William Hill is the best performer after reporting an 11% rise in revenues in the 13 weeks to 29 March. "We have seen excellent growth across our business in the first quarter, enabling us to remain confident in our expectations for the full year," chief executive Ralph Topping said. Rival Ladbrokes is also wanted.Heading the other way is engineering company Rotork after saying that it expects first half margins to be slightly lower than the previous year, as it continues to grow the business and absorbs higher raw material costs. Tanzania-focused gold miner African Barrick Gold is firmer after reporting that gold production fell 2% in the first quarter year-on-year to 173,907 troy ounces while net profit fell 5%.Specialist insurer and reinsurer Beazley is under the weather as the net cost of catastrophes in Australia, New Zealand and Japan is estimated to be $154m.Also lower is sector peer Lancashire Holdings which said it expects to take a $75m hit from claims arising from the Japanese earthquake.High-tech defence products supplier Ultra Electronics is trading 'in line' and believes its focus on specialist products will help it withstand defence cuts. The market doesn't seem to sure, as shares are lower.---bcFTSE 250 - RisersWilliam Hill (WMH) 213.10p +7.36%SVG Capital (SVI) 274.00p +6.66%Supergroup (SGP) 1,530.00p +3.80%Imagination Technologies Group (IMG) 494.20p +3.74%AZ Electronic Materials SA (WI) (AZEM) 278.20p +3.42%Ferrexpo (FXPO) 479.80p +3.41%St. Modwen Properties (SMP) 168.60p +3.37%Micro Focus International Plc (MCRO) 337.00p +3.25%African Barrick Gold (ABG) 554.50p +2.88%Ladbrokes (LAD) 148.00p +2.85%FTSE 250 - FallersBwin.party Digital Entertainment (BPTY) 162.60p -5.74%Rotork (ROR) 1,662.00p -4.04%CPP Group (CPP) 123.00p -3.07%Avis Europe (AVE) 187.70p -2.75%Spirent Communications (SPT) 132.50p -2.00%Cable & Wireless Communications (CWC) 45.47p -1.79%Cobham (COB) 225.90p -1.74%Beazley (BEZ) 130.80p -1.73%QinetiQ Group (QQ.) 119.90p -1.72%Edinburgh Dragon Trust (EFM) 246.10p -1.60%