An instrument that gives the holder a right but not the obligation to buy <a title="Ordinary shares" href="https://quoteddata.com/glossary/ordinary-shares/">ordinary shares </a>at a pre-determined price (the strike price or exercise price) on a given date or within a range of dates. It is like a <a title="Warrant" href="https://quoteddata.com/glossary/warrant/">warrant</a> but eligible for inclusion in an ISA