Sion Kearsey, a Non-Executive Director and one of the founding members of Sepura, has sold nearly one and a half million pounds-worth of shares in the digital radio maker, taking advantage of the stock's impressive surge so far this year.Kearsey, a former senior manager at Goldman Sachs' fixed income, currencies and commodities division, sold a million shares in the company at a price of 147p each, earning himself £1.47m. The disposal of the 0.72% stake trimmed his interest in Sepura to eight million shares, equal to a 5.78% holding.Since the start of 2013, the stock has surged by over 60%. Over the last 12 months, the share price has more than doubled.In the fiscal year to March 29th, the company grew revenues by 26% to €104.8m and saw adjusted operating profits rise 34% to €10.5m.Meanwhile, terrestrial broadcaster British Sky Broadcasting (BSkyB) said on Thursday that two of its boardmembers raised their stakes in the company as part of its co-investment plan.Chief Executive Jeremy Darroch and Chief Financial Officer Andrew Griffith each elected to invest their maximum entitlement under the plan to buy shares, purchasing 57,120 and 26,052, respectively, at a price of 839.98p per share.As such, Darroch invested £0.48m, raising his stake to 411,695 shares, while Griffith's £0.22m buy pushed his holding to 140,504.Under the terms of the BSkyB co-investment plan, Darroch and Griffith have received awards of up to a maximum of 162,794 and 74,249 matching shares, respectively, at a nil cost per share, in relation to their purchases. These awards vest in three years and are still dependent on specific targets for the company's earnings growth, the firm said.Top Director BuysBritish Sky Broadcasting Group (BSY) Director name: Mr Jeremy DarrochAmount purchased: 57,120 @ 839.98p Value: £479,797G4S (GFS) Director name: Mr Ashley AlmanzaAmount purchased: 100,000 @ 251.00p Value: £251,000British Sky Broadcasting Group (BSY) Director name: Mr Andrew GriffithAmount purchased: 26,052 @ 839.98p Value: £218,832Bank of Georgia Holdings (BGEO) Director name: Mr Alasdair (Al) BreachAmount purchased: 2,000 @ 1,711.00p Value: £34,220Rio Tinto (RIO) Director name: Mr Richard GoodmansonAmount purchased: 501 @ 2,948.88p Value: £14,774Rio Tinto (RIO) Director name: Mr Paul TellierAmount purchased: 428 @ 2,948.88p Value: £12,621Top Director SellsSepura (SEPU) Director name: Mr Sion KearseyAmount sold: 1,000,000 @ 147.00p Value: £1,470,000easyJet (EZJ) Director name: Ms Carolyn McCallAmount sold: 107,490 @ 1,196.69p Value: £1,286,322LMS Capital (LMS) Director name: Mr Bernard J. Duroc-DannerAmount sold: 93,333 @ 77.40p Value: £72,240BC