Capital gains on buy-back: shareholder treated as realising capital gains when company purchases its own shares. When a company purchases its own shares or other specified securities from a shareholder or holder, the difference between the cost of acquisition and the consideration received is deemed to be Capital gains arising to that shareholder or holder in the year in which the company purchases the shares or specified securities, subject to the provisions of the statute; consideration of the specified nature in buy-back transactions is deemed nil, and 'specified securities' shall have the meaning assigned in the Companies Act explanatory provision.