In this Act—
"securities" means listed securities and, in the case of a company within the meaning of the Companies Act 1985, or a company registered under Chapter II of Part XXII of that Act or an unregistered company, the following securities (whether or not listed), that is to say, any shares, any debentures, or any right to subscribe for, call for or make delivery of a share or debenture;
"listed securities", in relation to a company, means any securities of the company listed on a recognised stock exchange; and
"advertised securities", in relation to a particular occurrence, means listed securities or securities in respect of which, not more than 6 months before that occurrence, information indicating the prices at which persons have dealt or were willing to deal in those securities has been published for the purpose of facilitating deals in those securities.