The dollar price at which the owner of a warrant or an option can force the writer to sell an asset (in the case of a call option or warrant) or to buy an asset (in the case of a put option). The exercise price is set at the time the option is issued and, except for unusual instances that include warrants, remains constant until the option expires. A market price of an asset that is above, or is expected to be above, an option's exercise price gives the option value. See also step-up.