What do you mean, "the principle of liquidation priority and time priority applies to the transaction matching, but the principle of liquidation priority does not apply to the newly opened positions on the same day"? The special language in stock index futures gives priority to closing orders and pending orders when selling. If you just want to close your position today, you can't close your position first. You should give priority to empty orders and multiple orders.

General Rules for Simulated Trading of Commodity Futures Options in Shanghai Futures Exchange In order to standardize the trading of futures options (hereinafter referred to as options), protect the legitimate rights and interests of the parties involved in options trading and ensure the smooth trading of options in Shanghai Futures Exchange (hereinafter referred to as the Exchange), these Detailed Rules are formulated in accordance with the Regulations on the Administration of Futures Trading and the Trading Rules of Shanghai Futures Exchange.

Exchanges, members and customers shall abide by these rules. Option contract Option contract refers to the standardized contract formulated by the exchange. In this contract, the buyer has the right to buy or sell a specified number of underlying futures contracts at the exercise price of the contract within the time specified by the exchange, and the seller must perform it.

The main terms of the option contract include: contract object, contract type, trading code, trading unit, exercise mode, quotation unit, minimum change price, contract month, exercise price quantity, exercise price range, daily maximum price fluctuation limit, trading time, last trading day and listed exchange. The object of the option contract is the standard futures contract listed and traded on the Shanghai Futures Exchange. There are two kinds of option contracts: call option and put option.

The buyer of the option contract has the right to buy a specified number of basic futures contracts at the execution price of the contract at the time specified by the exchange; When the buyer exercises his rights, the seller of the contract must sell a specified number of basic futures contracts at the exercise price of the contract to fulfill the contract.

The buyer of a put option contract has the right to sell a specified number of basic futures contracts at the execution price of the contract within the time specified by the exchange; When the buyer exercises his rights, the seller of the contract must purchase a specified number of basic futures contracts at the execution price of the contract to perform the contract. The trading code of option contract consists of four parts: the type of option contract (C is call option and P is put option); The exercise price of the option contract (XXXXX); The trading code of the underlying futures contract; The contract month (yymm) of the option contract.

The trading unit of option contracts is "hand", and the number of "first-hand" option contracts is the same as that of "first-hand futures contracts", so option trading must be carried out in integral multiples of "first-hand". The right method is the feasible right from T trading day to the last trading day (including the last trading day), and T shall be stipulated separately by the Exchange.

When T is the listing date of the option contract, the option contract is an American option; When T is the last trading day, the option contract is a European option. Option contracts are denominated in RMB, and the pricing unit is RMB. The minimum change price refers to the minimum change in the unit price of the option contract, which should be less than or equal to the minimum change price of the underlying futures contract.