The settlement price itself is meaningless. Only when the deposit of the day is collected, it will be collected according to the settlement price standard. How much money you make and how much you lose has nothing to do with the settlement price, but the cost you pay has something to do with the settlement price (you always have to make a profit in business, and so does futures). So your final profit is (1200-1050) * 45 *10 (note, ten tons of soybeans per hand) = 67,500 yuan.

Also note that when you plan to short 45 lots, there are two situations to get a short position. The first one is that the person who shorted in the early stage gives you an empty bill at this price, and the computer displays the exchange of the empty bill. At this point, the position will remain unchanged. The second is that someone just opened more than 45 lots at this price, so that the two of you add up the positions and add up to 90 lots (including 45 long lots and 45 short lots). Many times it is a mixture of one or two situations, because speculators in the market are closing positions and opening positions all the time.