It is more appropriate to sell when the fund rises by 20%. For example, a fund with a net worth in 2 yuan bought 1 1,000 copies and paid 2,000 yuan. Held for three months, net worth of 2.4 yuan, sold 1 000 copies. After deducting the redemption fee and operating fee 54 yuan, the actual account was 2,346 yuan. 346/2000 *100% = 1 1.8%, the fund has increased by 20%, and the expected rate of return is11.8%, which is already very good.