Let's simply assume that at this time, you hold a fund with a unit net value of 1.2, with a share of 100, and you sell half of it when the fund net value is 1.3 on the day of selling (before 3 pm). At this time, the part sold is 50, and the settlement is calculated as 1.3.

After the sale, the share is 50, but the net holding cost is still 1.2, so the unit net value at this time is 1.3.

In the case of adding positions, the cost price of holding net value will change, but lightening positions will not.