In theory, fees should not exist. The speculation of contracts, whether bullish or bearish, does not actually result in buying or selling the cryptocurrency; it is merely a gambling behavior. This kind of gambling should not affect the price of the coin. It's like rice costing 2 yuan per pound. If you and I each take out 100 yuan to bet, I bet it will go up and you bet it will go down. Our betting behavior will not affect the price of rice; the outcome, who wins and who loses, and how much is determined by the market price of rice.