Bybyt Unified Trading Account (
https://www.bybit.com/en/promo/events/unified-trading-account) is like all in one with Isolated Margin, Cross Margin, Portfolio Margin. With those types, they will charge you trading fees when you let your positions open and open longer, you will have to pay more trading fees.
Do you think if you let your position opens for 2 months, will the increase of that token price be enough to cover your trading fee?
After the trading fee is charged based on percentage of the amount that you want to trade, no other trading fee is charged. The only other fee is the funding fee which might be given you or charged you and it is every 8 hours.
With margin, you might be in a hilarious situation. You hold ETH and use it as your margin collateral but when you see ETH rises a lot, you open a Short position. The funny but painful story is here: ETH rises, your portfolio value increases but you are in loss and can be liquidated with your Short position.
Trade with the amount of money that you can afford to lose. This is not holding but trading.
I think there won't be any deduction so far you are not losing much. But once it is getting to the point of liquidation, the negative USDC or USDT balance will be deducted from the bitcoin or other coin used as collateral.