American-style option

A type of option that can be exercised at any time between the purchase date and the expiration date. Most options in the U.S. are of this type. This is the Opposite of a European-style option, which can only be exercised on the date of expiration. Since an American-style option provides an investor with a greater degree of flexibility than a European style option, the premium for an American style option is at least equal to or higher than the premium for a European-style option which otherwise has all the same features. Also known as American option.