Facebook vice president David A. Marcus moved from Facebook Messenger to a new blockchain division in May 2018.
First reports of Facebook planning a cryptocurrency, with Marcus in charge, emerged a few days later.
Confirmation that Facebook intended a cryptocurrency first emerged in May 2019.
But Facebook Inc. was banning ads on its social network that promote cryptocurrencies, initial coin offerings and binary options, since January 2018 [0]
Was Facebook decision to create a cryptocurrency, made by the end of 2017?
[0] https://fortune.com/2018/01/30/facebook-cryptocurrency-bitcoin-ad-ban/