Profit and loss of the day = ∑ (selling price-settlement price of the day) × selling quantity+∑ (settlement price of the day-settlement price of the day )× buying quantity+(settlement price of the previous trading day-settlement price of the day )× (selling position of the previous trading day-buying position of the previous trading day)

Balance of settlement reserve on the current day = balance of settlement reserve on the previous trading day+trading deposit on the previous trading day-trading deposit on the current trading day+actual offset amount on the current trading day+profit and loss on the current trading day+deposit and withdrawal-handling fee, etc.