If it is the main contract, the quotation is continuous and the current price is 3000. Generally, you may buy 3000 or 2999 and sell it at 300 1 or 3000, so you can make a deal at 300 1 or 3000.

If you make an inactive variety and there is no selling order on it, your list will be hung on the buying order, and then someone will sell it, and the transaction will be 4000.

Explain that futures have price limits, so there will be no current price of 3,000 and quotation of 4,000 (the trading system automatically limits).