The most important reason for adopting this method is the principle of fairness. For example, on June 13, the net value was 1 yuan, but on June 14, the stock market rose sharply, and the net value of fund shares on June 14 would also rise accordingly, for example, to 1.2 yuan. If an investor buys a fund share on June 14 according to the net value of the previous day 13, and sells the fund share on June 15 according to the net value of 14, the gross profit of 0.2 yuan/share can be obtained immediately.