The leek mentioned in the fund is used to describe fund investors who have just entered the market. Fund investors who have just entered the market are in a weak position in the fund market. When the fund withdraws, the money in the hands of fund investors who just entered the market is cut away like leeks. In addition, new people are constantly entering the fund market, just like the chopped leek will grow back, so it is more appropriate to use leek to describe the fund investors who have just entered the market.
If investors don't want to be called leeks, they should either use professional investors or learn more by themselves.