Another name for a call option, that is, an option contract that gives the holder (the buyer) the right, but doesn’t oblige him, to buy a certain amount of an underlying security from the writer (the seller) of the option, at a specified price (usually known as the strike or exercise price) up to a specified date (the expiration date). It is also called a call, for a shortcut. The standard amount of underlying security is normally 100 shares.

A call option is roughly equivalent to an investment in an asset since the holder has the right to purchase that asset in favorable conditions.