I don't know how you calculated the thread opening and closing fee of 28%. If Kaiping is calculated unilaterally by 1%, the annual 8 yuan will not exceed about 230 trading days. I don't know how you worked out 8*230= 1840 yuan in these 270 trading days. This is to calculate the total cost of your daily transaction. If you simply calculate futures like this, you are wrong.

Take trading once a day as an example. The daily transaction cost is the average fluctuation range of rebar in 8 yuan. I don't know if you have calculated it, but it should be above 1%. According to the current price, it is probably the first-grade rebar in 35 yuan, that is, 350 yuan. Because you assume that you trade every day, you only need to earn more than 8 yuan from the fluctuation range of 350 yuan every day, and you can achieve positive returns.

It can be assumed that if you make a rebar a year and the profit is 10000 yuan, then your average profit per transaction is 10000/230 = 43.5 yuan, which means that you only need to make a profit in 5 yuan in the fluctuation of 35 yuan every day.

Your problem is that the number of times you pass the transaction solidifies the total cost, forgets the opportunity in each transaction, and falls into an infinite loop of thinking.