Alexander Vinnik, 43, the Russian co-founder of bitcoin exchange BTC-e, was arrested in Greece in 2017 on U.S. money-laundering charges and later extradited. He is facing U.S. money-laundering charges and allegedly laundered more than $4 billion of criminal proceeds via BTC-e. Vinnik pleaded not guilty and could be included in a prisoner exchange between the U.S. and Russia that could free detained Wall Street Journal reporter Evan Gershkovich.