The buying and selling price depends on the unit net value, that is, the net value of each fund now. Cumulative net value is the value of the fund from the date of issuance, and there may have been n dividends in the middle.

Calculation at the time of purchase: investment amount * subscription rate/fund net value of the day;

Calculation at the time of offering: fund share * net value of the fund on that day *( 1- redemption rate).