A method of trading a foreign currency option on an electronic trading system may include executing a trade of the foreign currency option between a buyer and a setter, 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 hay 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.