I wonder if you mean domestic futures trading? In the past, domestic futures trading was allowed to increase profits. About six or seven years ago. Floating surplus is not allowed to add positions. Note that floating profits are not allowed to add positions, not to say that profits are not allowed to add positions.
As the futures adopt the margin trading system, if investors are allowed to continue to use the floating profits of the day and open new positions before settlement, there will be the possibility of insufficient funds when the day is settled.
If the market is favorable to you, there will be a lot of floating profits, which will become available funds in your account after settlement on the same day, and you can continue to open positions with this money the next day.
In fact, the core of futures trading is to control leverage. We also advise you not to be too heavy when trading. Keeping enough funds available is the way to reduce positions.