There is no fixed cycle, only changing positions. Futures refers to the trading of contracts. To trade a contract, someone must be long, and correspondingly, someone must be short. The number of open contracts is called open position, which is equivalent to circulation, but it is changing. For the main contract, generally no one will answer. Even if it is bearish or bullish, people who want to buy the opposite contract will do the opposite. However, if it is not the main contract, it will often be closed for a long time. The futures index is a complete zero-sum market. Some people make money, others lose money. The money you earned must have been lost by others, and it has nothing to do with the stock.