But if you do live in one of those states, Robinhood Crypto is a great option to get started in Bitcoin or Ethereum trading. Cryptocurrency A cryptocurrency is a digital or virtual currency that uses cryptography and is difficult to counterfeit because of this security feature. Instead of buying directly with cash, you instead need to use a voucher like Flexepin or Neosurf. Bitcoin Buying and Spending. Many exchanges are simply trying to steal your personal information like your password. Compare Investment Accounts.