Fixed investment is different from one-time purchase of funds. The share of the latter has been determined. The higher the net value, the higher the value of the fund. The fixed investment is deducted for each period, and the share changes according to the price of each period. High net worth funds can only make the subscription share smaller, and only the price at the time of final redemption plays a role in the total amount. The share is decided in front. Therefore, turning a fixed investment into a high net worth is not necessarily a profit. Only when the final redemption price exceeds the previous purchase price will it be profitable. If the price falls, there may be negative redemption value.