Generally speaking, OTC funds cannot be bought and sold on the same day, because OTC funds are settled after the close, but investors can withdraw their orders. At this time, they haven't bought successfully, so they can't buy or sell!
If the fund goes public, it depends on the investment of the fund. Generally, funds that invest in the domestic market are not allowed to buy and sell on the same day. Generally speaking, the QDII funds in the market are the ones that can invest in overseas markets and Hong Kong stock market in China.