An option that combines an Asian option with an American option. Effectively, the combination produces an Asian option which allows for early exercise. In other words, this option allows its holder to look back in time, with its payoff being determined by averaging the underlying price as observed over the option’s time to maturity, and with a possibility of early exercise. The Ameriasian option allows investors to assume option positions without being exposed to variations in the underlying price, particularly near expiration dates.

This option is also referred to as an Hawaiian option or an American Asian option.