Hi, i have a question. what if i sent my coins to some exchanges like mercatox or yobit do i need an ETH (to cover gas transaction) to sell it? or no need?
No Gas fees are required to be paid while selling Eth on exchanges. Though there is some trading fee which automatically gets deducted from your exchange's account and varies from exchanges to exchanges. You would also be required to pay a small transaction fee when you withdraw your coins from exchange to your wallet.