Robinhood was a popular stock trading app that recently launched cryptocurrency trading. We may receive compensation when you use Luno. Coinmama is an all-in-one exchange and digital wallet that makes it easy to buy Bitcoin and a limited list of additional currencies in U. Scalpers seek to profit from fleeting imbalances between buyers and sellers. The likes of CryptoBridge, EtherDelta, and many other decentralized exchange projects are in the development phase.