A cryptocurrency wallet that is built on the Ethereum ERC-20 protocol is called MetaMask. Because of this, some individuals think that MetaMask is exclusive to Ethereum as only ERC-20 tokens are supposed to be held in MetaMask. And it is true, hence, you cannot use the MetaMask wallet to store Bitcoin or any other cryptocurrency asset which is not based on the ERC-20 protocol. Can MetaMask hold Bitcoin
