There is a very strange point, please help me clarify. A few days ago, I opened a grid contract to short. The opening price was 81300, but after a few days, there were over 300 transactions, and the grid contract profit was over 3000. However, when the price returned to 80300 today, my overall profit was only 700. Moreover, around 80000, I no longer had any short positions. I am very curious about the reason.