With Perptual trading, when you have a position, the longer you let that position opens, the more interests you will have to pay for that exchange. Usually exchanges will have different shifts of funding rates within every 24 hours. It can be 3 or 4 shifts every day.

So even if your position at the end when you close it at profitable exit price, the longer you let that position opens, the less interest you will get at the end because the more in interest you will have to pay for exchange.