John Sheldrick, a Non-Executive Director of FTSE 250 polymer technology firm Fenner, bought himself 10,000 shares just one day after the company unveiled a 53 per cent increase in pre-tax profit. Sheldrick purchased the shares for 440p each, for a total of £44,000. This represents 0.005% of Fenner's total issued shares and is Sheldrick's entire holding.On the same day, Sheldrick's fellow board member, Vanda Murray, also bought a stake in the firm, buying up 2,000 for 446.88p each (equal to 0.0001% in the company).The company's rise in profit, for the half year ended February 29th, was the result of bumper demand from its energy and mining customers. Underlying pre-tax profit increased to £48.1m while pre-tax profit rose to £41.7m from £26.6m the previous year. Revenue for the period swelled to £412m from £332.5m previously. The group said trading since February has been in line with company expectations. Top Director BuysFenner (FENR) Director name: Mr John SheldrickAmount purchased: 10,000 @ 440.00p Value: £44,000Eastern European Trust (EST) Director name: Ms Rachel BeaglesAmount purchased: 10,096 @ 257.50p Value: £25,997Games Workshop Group (GAW) Director name: Mr Mark WellsAmount purchased: 4,490 @ 569.94p Value: £25,590Vislink (VLK) Director name: Mr John VarneyAmount purchased: 32,827 @ 33.20p Value: £10,899Top Director SellsIFG Group (IFP) Director name: Mr Declan KennyAmount sold: 50,000 @ 122.68p Value: £61,340Games Workshop Group (GAW) Director name: Mr Mark WellsAmount sold: 1,982 @ 570.00p Value: £11,297