Systems and method of enabling trading in currencies are provided. A method of trading a foreign currency option on an electronic trading system according to the invention may include executing a trade of the foreign currency option between a buyer and a seller, locking the trading system with respect to the traded foreign currency option, querying the buyer whether the buyer desires to buy or sell additional volume of the option, querying the seller whether the seller desires to sell or buy additional volume of the option, and authorizing additional participants to join the trade and querying the additional participants whether each of the additional participants desires to buy or sell a volume of the option. The method may also include starting a countdown timer and displaying the timer on the graphical user interface of the buyer, the seller and the additional parties and receiving buy and sell orders from the at least one of the buyer, the seller and additional participants. Following the expiration of the countdown timer, the method preferably includes matching existing buy orders and sell orders for the option. In one embodiment of the invention, the matching occurs according to a predetermined order priority.