Buying futures takes up margin, and the margin ratio changes every day. The closer to the delivery date, the higher the proportion. Judging from the corn 140 1 contract you listed, the deposit for this period is probably similar to the price marked above. The price listed above is one ton, and the price of corn is 10 ton. The tonnage of each contract is different. You'd better go to the corresponding futures exchange to check the contents of the contract, and be sure to have a detailed understanding of the contract you want to invest in before selling it.