Infinite. Futures is relative to the concept of "spot", which refers to the delivery and sale of goods that are bought and sold now but will be carried out in the future. Futures is a two-way contract. As a buyer, the biggest risk is royalties, and there is no need to pay a deposit. As a seller, the risk is unlimited, but the deposit needs to be paid and the income is fixed, so the risk of the futures seller is unlimited.