An exotic warrant (barrier warrant) that is subject to a predefined window period during which if the barrier price is hit, a knock-out event occurs. Once it is knocked out, it will cease trading, while the holder will get paid a fixed rebate amount. Reference to a pre-set barrier price, along with the type of an option, will help determine the outcome during a window period.

For a window barrier call warrant, payment of the fixed rebate depends on the closing price of the underlying asset being equal to, or below, the barrier price on any trading day during the window period. For a window barrier put warrant, the closing price of the underlying asset must be equal to, or above, the barrier price on any trading day during the window period.