Fund cost after fixed investment = total amount of fixed investment/(initial fixed investment amount/confirmed net value+? +N-th fixed investment amount/confirmed net value), for example, when the net fund value is 1 yuan, investors start to make fixed investment, and the fixed investment amount is 1 1,000 yuan; When the net value of the fund is 0.8 yuan, they make a second fixed investment of 1 1,000 yuan; When the net value of the fund was 0.5 yuan, they made a fixed investment of 1 1,000 yuan for the third time.

Fixed investment in the rising process will increase its position cost, while fixed investment in the falling process will reduce the position cost.