This isn't directly related, but you may find these interesting.

Fake volume related to a recent Tether piece in the WSJ: https://medium.com/@nic__carter/assessing-bitcoins-liquidity...

Bitwise presentation to the SEC regarding fake volume among exchanges: https://www.sec.gov/comments/sr-nysearca-2019-01/srnysearca2...

I posted my source 3 comments up.

Why would we trust that source over the exchange themselves?

My other comment here was useful with other sources showing that exchanges do fake data.

https://medium.com/@nic__carter/assessing-bitcoins-liquidity...

https://www.sec.gov/comments/sr-nysearca-2019-01/srnysearca2...

The second source uses Coinbase as the standard for accuracy and compares another exchange to it...

Yes because Coinbase is a legit exchange. It also doesnt use Tether. That doesnt mean that their data on Tether volumes is correct.