Coinbase

San Francisco

Offers digital-currency wallets with 10 million-plus users; exchange trading in Bitcoin, Ethereum, Bitcoin Cash and Litecoin; and merchant tools.

Bona Fides: $1 billion in revenue in 2017 Cofounder & ceo: Brian Armstrong, 35 (see “Prophets of Boom,” p. 60) Funding: $217 million; latest official valuation of $1.6 billion, but surely more