This is a document entitling the holder to buy a specific amount of bond or stock securities at a specific price above the current market price. These certificates are sometimes permanently applicable and may also be valid for periods as short as a few years. The value of such a warrant is that it provides an investor the opportunity to purchase specific security if they rise to a level above which is specified in the subscription. Investors may also sell their subscriptions for profit, not use them at all, or allow them to expire. Subscription warrants are listed on options exchanges and trade independently of the securities with which they are issued. They are sometimes simply referred to as warrants.