An extendible option in which the right to extend the maturity date is held and made by the option holder (buyer) when the option is at-the-money or out-of-the-money (from the holder’s perspective) at the maturity date, with the payment of an additional premium. This option may extend automatically at the original expiration date if a specific condition, such as the option being out-of-the-money, is met. The extra premium will be paid at the time of extension.

This option is also known as a buyer extendible option.