Warrant
A warrant is a derivative security that gives the holder the right to purchase securities from the issuer at a specific price within a certain time frame.[1]
Warrants are essentially the same as a call option; however, warrants are guaranteed by the issuing company rather than by an exchange (as is the case for options). Warrants also often have an expiration schedule that's measured in years rather than months.
The input volatility for warrants as compared to options is often considered to be either too high or too low depending on whether the client is a buyer or a seller. Market makers frequently call these, 'money for old rope'.
They have been successful in various markets, but in those which have transparent option markets, such as with equities the U.S. equity, they tend to wither and die. Institutions, while attracted by the large margins, do need to be aware that they can be accused of mis-selling if they put a client into a warrant when an option of the same strike and maturity exists.