Electra Private Equity, the investment trust that invests in private equity ventures, was the biggest riser after it saw an 8.5% rise in net asset value (NAV) per share after a strong portfolio performance during the year ended 30 September.Vehicle hire firm Northgate was also on the rise after it posted a 19% increase in half year underlying profit, despite challenging market conditions in the UK and Spain. Peel Hunt maintained its buy recommendation after the firm's first half results came in slightly ahead of forecasts.Victrex followed suit after the plastics group hiked its dividend as it reported record group revenue and profits for the year. Profit before tax was £94.2m, up 26% on 2010, while revenue for the year to the end of September was up 14% to £215.8m. Thomas Cook rose on reports that David Cameron is set to announce plans to ensure better provisions are in place to protect customers of tour operators if it collapses when they are abroad. The reassurance would mean people are more likely to book package holidays, essential to the success of firms such as Thomas Cook. According to Peterborough Today, Cameron made the statements in a personal letter to local MP Stewart Jackson. Interserve was rising, most likely boosted by yesterday's news that it has won a £19.4m contract with NHS Procure 21+ to build a medical research facility in Devon. Yule Catto was on the rise after its pharmaceuticals division was snapped up by Vivimed Labs. Meanwhile, budget airline easyJet was falling despite flying with fuller planes last month, as passenger numbers rose by 3.4%, compared with November last year. Some 3.82m people bought seats with the airline in November, up from 3.69m the year before. The firm's no-refund policy means that passenger figures do not include those who do not turn up for the flight. Retailers were also performing badly on news that consumers are keeping "a tight rein on their spending, despite Christmas being so near". According to the British Retail Consortium (BRC) total sales were up 0.7%, against a 2.8% increase in November 2010. Home Retail was hit hard by the news to become the biggest faller, with Dunelm not far behind. FTSE 250 - RisersElectra Private Equity (ELTA) 1,482.00p +4.00%Domino Printing Sciences (DNO) 521.50p +2.56%Thomas Cook Group (TCG) 17.01p +2.41%Brewin Dolphin Holdings (BRW) 135.60p +2.34%Interserve (IRV) 327.10p +2.19%Premier Foods (PFD) 5.71p +1.96%Yule Catto & Co (YULC) 177.10p +1.84%Mitie Group (MTO) 254.70p +1.80%Marston's (MARS) 97.05p +1.62%Personal Assets Trust (PNL) 33,820.00p +1.44%FTSE 250 - FallersHome Retail Group (HOME) 93.50p -7.33%Elementis (ELM) 136.80p -6.94%Dunelm Group (DNLM) 430.00p -5.35%Kesa Electricals (KESA) 83.00p -4.60%Northgate (NTG) 232.80p -3.80%Hansteen Holdings (HSTN) 71.05p -3.79%Hays (HAS) 68.00p -3.75%Aquarius Platinum Ltd. (AQP) 180.00p -3.74%Victrex (VCT) 1,149.00p -3.61%Centamin Egypt Ltd. (CEY) 96.40p -3.60%NR