When you buy or sell cryptocurrency, fees are charged separately from the amount traded in the order. For example, if you enter $100 USD as the amount of BTC to buy, and the fee is 0.25%, the transaction will show as a BTC order of $100 and a separate fee of $0.25.
You may choose to have the fees paid for with ZOOM tokens (discounts available) or from your account balance.
Current fees can be found here.