Sources: Coinbase established a professional trading team last year and has completed a $100 million "proprietary transaction"

In order to diversify its revenue, Coinbase hired at least four senior Wall Street traders last year and formed a team that generates part of its profits through the company's cash transactions and pledges, the Wall Street Journal reported, citing sources. The activity was described by company personnel as "proprietary" trading. Earlier this year, the team closed a $100 million deal that the group viewed as a test deal, people familiar with the matter said. The deal comes after Coinbase executives testified to lawmakers last year that the company did not buy or sell digital currencies for its own accounts.