If the actual price rises to infinity, the income of the party (parties) holding the futures contract is equal to the actual price MINUS the agreed price of the futures contract, and his income is infinite. On the contrary, the loss of the party selling the futures contract is equivalent to the actual price of the futures contract minus the agreed price, and his loss is infinite.

Therefore, when the actual price rises to infinity, the possible gains or losses of buyers and sellers are unlimited.