"First in, first out" means that when investors buy the same fund for many times, they will redeem it in the order of subscription when handling the redemption business, that is, they will purchase first and redeem first; "LIFO" is the priority to redeem the share of fund products purchased later.
Different funds have different redemption rules, which are generally stipulated in the fund prospectus. It is recommended to read and understand the trading rules carefully before buying and redeeming funds.
Generally speaking, most funds in the market are redeemed according to the "first in first out" rule, and a few funds are redeemed according to the "last in first out" rule.