Perpetual Warrant - When a firm issues a certificate that allows the holder of that certificate the right to purchase its securities at a given price, it is called a warrant. These are generally long term certificates and are not issued by futures exchanges. Most of these warrants will be valid for a specific period of time determined at the time of purchase. In the event that the warrant does not operate within a specified period of time it is referred to as a perpetual warrant. This type of warrant is very practical for enhancing the marketability of a given stock, particularly preferred stock or corporate shares.