Facebook's blockchain boss David Marcus is leaving the board of crypto startup Coinbase. His departure is a signal that the social networking giant's secretive blockchain efforts are progressing. "Because of the new group I’m setting up at Facebook around Blockchain, I’ve decided it was appropriate for me to resign from the Coinbase board," Marcus said in a statement. In a sign that Facebook's secretive blockchain effort is progressing, David Marcus, the head of that project, announced he's leaving the board of $8 billion cryptocurrency startup Coinbase. Marcus joined Coinbase's board in December 2017.