You can lose profit sending trading and withdrawing if you are trading a small amount I have $50 worth of Ferum or FRM it will take $6 to send the whole amount to Bilaxy and after you trade it to Eth and wants to withdraw it you will have to spend $12 to withdraw your Eth,
now that's $18 gas fees for your $50, my only option is to trade it to other altcoins like DGB or Litecoin which offer $4 to $5 fee you still going to lose $11, that's over 20%.
This is the most common problem if you do just really try to sell your shit token on an exchange and specially now that ETH does have ridiculous high fees then that would surely hurt up.
Back in the days where ETH fees almost cost free but now we are already experiencing problems towards it. If you do have shitcoins that only being traded on a specific exchange
then you wont really be having any choice but to deal with those fees or rather you do opt in to held it off but since those coins doesnt really have an unsure value
then primary thing in mind is to sell off and secure those small bucks. Fees will really be in part of the deduction.