Io futures varieties refer to the code of vegetable oil. According to the relevant information of the query, I know that io is the abbreviation of indexoption. The vegetable oil code consists of letters, expiration date, contract type and execution price. The contract months are the current month, the next two months and the next three quarters. The trading day and expiration date are the third Friday of the expiration month of the contract, which will be postponed in case of national legal holidays.