Iain Johnston, a director at the marketing software provider Alterian, has cut his holding in the firm, selling 100,000 shares at 150p each.He still has 1.19m shares in the firm, which is more than 2%.Shares in Alterian, whose products include Dynamic Messenger, an email marketing tool, have rallied sharply since Johnston last cashed in, taking 103.6p a time for 95,000 shares.Top Director BuysIndian Energy Ltd. (IEL) Director name: Mr John WallingerAmount purchased: 38,750 @ 84.00p Value: £32,550Argo Group (ARGO) Director name: Mr Kenneth WattersonAmount purchased: 88,141 @ 17.00p Value: £14,984Top Director SellsBig Yellow Group (BYG) Director name: Mr Nicholas VetchAmount sold: 640,000 @ 390.00p Value: £2,496,000First Quantum Minerals (FQM) Director name: Mr G Clive NewallAmount sold: 30,000 @ 4,401.73p Value: £1,320,516Big Yellow Group (BYG) Director name: Mr Adrian LeeAmount sold: 251,000 @ 390.00p Value: £978,900Big Yellow Group (BYG) Director name: Mr James GibsonAmount sold: 209,000 @ 390.00p Value: £815,100First Quantum Minerals (FQM) Director name: Mr Andrew AdamsAmount sold: 10,000 @ 4,530.31p Value: £453,031Carillion (CLLN) Director name: Mr Don KennyAmount sold: 238,404 @ 293.00p Value: £698,524New World Resources (NWR) Director name: Mr Miklós (Mike) SalamonAmount sold: 95,533 @ 590.20p Value: £563,836First Quantum Minerals (FQM) Director name: Mr Martin R RowleyAmount sold: 6,000 @ 4,183.27p Value: £250,996Alterian (ALN) Director name: Mr Iain B JohnstonAmount sold: 100,000 @ 150.00p Value: £150,000Xchanging (XCH) Director name: Mr Gary WhitakerAmount sold: 50,000 @ 226.00p Value: £113,000