Marcus stated that his decision to resign was “because of the new group I’m setting up at Facebook around blockchain.”
“Getting to know Brian, who’s become a friend, and the whole Coinbase leadership team and board has been an immense privilege. I’ve been thoroughly impressed by the talent and execution the team has demonstrated during my tenure, and I wish the team all the success it deserves going forward.”
There is speculation that the main reason Marcus left Coinbase is to avoid conflict of interest. This conflict might be because of another rumor that Facebook might acquire Coinbase; Facebook or Coinbase never came out to refute the acquisition rumors which adds more fuel to the fire.