So I just noticed coinbase added more decimal places for some trading pairs on their android mobile app. Excuse the bad quality picture, the app doesn't allow you to take a screenshot unfortunately so I had to use a terrible second phone for the picture
Coinbase could potentially be getting ready for adding more coins such as Stellar? Makes sense, especially after they announced that they are looking in to the possibility of adding Stellar.
This is the first time I ever noticed that many decimal places in the mobile app. Could be a coincidence but who knows