The analysis of pyramid-shaped Masukura should follow the following two principles: ① Masukura can only be increased if the existing position is profitable; (2) The increase of positions should be gradually reduced. This topic is to sell and open a position, and the price drop can make a profit. According to the above principles, positions can only be increased when the contract price is lower than 36,750 yuan/ton, and the amount of positions increased should be less than 8 lots.