It is not entirely correct that the fund only needs to consider the timing of selling and ignore the timing of buying, but below 3000 points is the best time for the fund to make a fixed investment. According to public data, the time of entry and exit is more important for the fixed investment in the middle line (within one cycle), and the average cost varies greatly with the time of entry. For example, when the market shocks bottom out, the average cost is the smallest; The average cost is the highest when the rising market enters; The average cost of entering a falling market is very small in the middle. To put it simply, when the market is below 3000 points and the market fluctuates near the bottom, the cost of making a fixed investment for the mid-line fund is relatively low.