IPO expected early 2021
Coinbase announced the submission of the Form S-1 on December 17th 2020. The form is expected to become effective after the SEC completes its review process.
Another interesting read: Coinbase's upcoming IPO won't be ignored by Wall Street
UPDATE: apologies for the incorrect date originally mentioned in this report. I found it on a forum, but after further research concluded it to be unsubstantiated.