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%.
So just be smart and use the best possible option and share your best knowledge/experience with the rest of the crypto community. The minimum withdrawal fees vary depending on the website, the best choice is to use either XRP or LTC for faster, cheaper transactions on both way. Using BTC or token will be costly and you will lose more in the long term.