That's what stock funds do. If the net value of the fund you bought in February is 1. 100, and the net value of the fund you sold on February 22nd is 1.300, you will earn 0.2 yuan (excluding the handling fee) for each share. Buy 1000 copies and earn 200 yuan (excluding handling fee). If you spend 1000 yuan with your bank card at the time of purchase and 1300 yuan at the time of redemption, you will make a net profit in 300 yuan. If you sell it with a net value of 1.05, you will lose money.