When you swap one asset for another in your RockWallet, fees are charged to cover transaction and blockchain mining costs. Mining fees will apply for sending and receiving cryptocurrency to and from your wallet for all ‘Swap’ transactions. Mining fees fluctuate based on the digital assets you are swapping and will be shown on the confirmation page before you finalize the transaction.
For all ‘Swap’ transactions, mining fees are charged in the assets being swapped. Since all ERC-20 coins are issued on the Ethereum blockchain, an ETH balance is required to cover network fees for any swap that includes ERC-20 coins, including: ETH, SHIB, USDC & USDT.