①: Formula: balance of settlement reserve for the current day = balance of settlement reserve for the previous day+margin for the previous trading day-margin for the current trading day+profit and loss for the current day+deposit-withdrawal-handling fee (deposit, withdrawal and handling fee are ignored in this question).

②: There is no "last trading day deposit" and "last trading day deposit" for new customers, but only 100000 deposit.

③: Profit and loss of the day = liquidation profit and loss+position profit and loss.

(1) Ending profit and loss = daily average warehouse profit and loss+historical average warehouse profit and loss (not included in this question)

Then the profit and loss of the day = the warehouse profit and loss of the day = (2030-2000)* 20 * 10 = 6000.

(2) Position profit and loss = opening profit and loss of the day+historical fly loss (this question is blank)

Then position profit and loss = opening profit and loss on the same day = (2040-2000) * (40-20) *10 = 8000.

So the profit and loss of the day = liquidation profit and loss+position profit and loss = 6000+8000 = 14000.

④: trading margin of the day = settlement price of the day * positions held after the close of the day * margin ratio = 2040 * (40-20) *10 * 5% = 20400.

(There is no deposit on the first trading day, and it is observed in the formula that the deposit is still in the deposit account the next day after the debt-free settlement. )

⑤ The balance of settlement reserve on the same day =100000-20400+14000 = 93600.

The comprehensive formula is:100000-2040 * (40-20) */kloc-0 * 5%+(2030-2000) * 20 *10+(2040-2000) * (44