The price limit of asphalt futures refers to the maximum intraday price fluctuation range allowed by futures contracts, and quotations exceeding this fluctuation range are considered invalid and cannot be traded. The price limit system of asphalt futures is to limit the maximum fluctuation range of asphalt futures prices and maintain the stability of asphalt futures market. The fluctuation range of petroleum asphalt futures contracts shall not exceed 3% of the settlement price of the previous trading day. When the futures contract has a unilateral market on a certain trading day (this trading day is called D 1 trading day, and the following trading days are called D2, D3, D4, D5 and D6 trading days respectively), the adjustment of the futures contract's price limit and the collection of trading margin correspond to the following table: On the D4 trading day, the exchange decides to implement one of the following two measures on the petroleum asphalt futures contract according to market conditions: Measure 1: On the D4 trading day, the exchange decides and announces to unilaterally or bilaterally treat some or all members. One or more measures, such as adjusting the range of price limit, restricting the withdrawal of funds, closing positions within a time limit and forcibly closing positions, can resolve market risks, but the adjusted range of price limit shall not exceed 20%. After the exchange announces the adjustment of the margin level, those with insufficient margin must be added before the opening of D5 trading day. If the fluctuation range of the futures contract does not reach the daily limit on D5 trading day, the ratio of fluctuation limit to trading margin of the futures contract on D6 trading day will return to normal level; If the fluctuation range of the futures contract reaches the daily limit in the same direction as that in the D3 trading day, the Exchange will declare it abnormal and take risk control measures according to relevant regulations; If the fluctuation range of futures contracts on D5 trading day reaches the daily limit on D3 trading day, it is regarded as the beginning of a new round of unilateral market, and that day is regarded as D 1 trading day. The trading margin and daily limit for the next day shall be implemented in accordance with Article 12 of the Risk Control and Management Law of Shanghai Futures Exchange. Measure 2: At the time of settlement on the D4 trading day, the Exchange will automatically match the open declaration of the closing price on the D3 trading day with the closing price on the D3 trading day of profitable customers (non-futures company members) in proportion to their positions. If the same customer holds a two-way position, he will close the position first and then close the position according to the above method.