A window barrier option that has a vanilla payoff at expiration and is subject to a single or double American barriers over a front part of its lifespan (the front window), that is, the observation period starts at the option’s inception date and ends at a specific date prior to expiration. For example, if the option’s life is 1 month, a front window might mark the period between the option’s inception date and the last week prior to expiration date.

Like its origin, this option has many variations including those with up barrier, down barrier, knock-in, knock-out, double barrier, etc.

This option is also known as an early ending barrier option.