1, the profit and loss of the position is calculated according to the opening price, and the profit and loss of the mark-to-market position is calculated according to the settlement price of the previous day. Therefore, unless you open a position on the same day, or your opening price is the same as the settlement price of the previous day, the gains and losses of the two are absolutely unequal.

2. The reason is the same as above

3. Companies have different definitions, some of which are the same concept as trading reserve, others are not, depending on your bill.