Pay attention to the operation status of selling points. If you are not familiar with the theory, then follow the lower level, because it is better to sell early than to sell late. Selling wrong is not as serious as buying wrong; selling wrong just means earning less, while buying wrong means facing being stuck with losses. However, for large-level central areas, if you wait for the third type of selling point to appear before selling, that reaction is already extremely slow. Where did the first and second selling points go? The market won't let you sleep anywhere~