Hello, stock index futures trading adopts cash delivery method. Under the cash delivery method, each open contract will be automatically closed when it is settled on the maturity date. That is to say, on the expiration date of the contract, the short party does not need to deliver the funds of the stock portfolio or the total contract value, but only needs to calculate the profit and loss amount of both parties according to the delivery settlement price, and settle the transaction by directly transferring the profit and loss between the margin accounts of both parties. Cash delivery and debt-free day settlement are essentially the same, with two differences: first, the calculation method of settlement price is different; Second, after cash delivery, the positions of both long and short positions will be closed automatically, and the positions of both sides will be retained after debt-free settlement on the same day.

Because the settlement price of delivery is calculated according to the spot price at that time in some agreed way, the delivery of stock index futures makes the stock index futures price and spot price closer and closer when the contract expires.