Maybe those information will help:

Last transactions from the address 37zfKL5EqsokYztEj6yrJxeJah52CgJixG were done on 2017-09-11, the day China declared to shut down all of its exchanges.

Those funds (and several others!!) lead to this address: 3DfVp3nuGyNbHgYKFrBs4L7nzsSkcdtejU

Approx. 28 BTC were then sent to a Bech32 address: bc1qzzxdvcpp9gk5lkk2zcf2hgz66ml3xasp75ty053094lz80pn52yqrju285
(At this time, the only exchange supporting withdrawals to Bech32 addresses was Coinbase!)

This happened 2018-12-14, a day Bitcoin saw a new yearly low.

So i guess, either Coinbase or any chinese exchange is involved.


Edit:

I just found a connection to this address: 1N52wHoVR79PMDishab2XmRHsbekCdGquK
(Transaction from that address to above mentioned 3DfVp3nuGyNbHgYKFrBs4L7nzsSkcdtejU)

This is a hot wallet of Bittrex!

In short:  

37zfKL5EqsokYztEj6yrJxeJah52CgJixG and
1N52wHoVR79PMDishab2XmRHsbekCdGquK (<<< Bittrex Hot wallet)
sent funds to
3DfVp3nuGyNbHgYKFrBs4L7nzsSkcdtejU]3DfVp3nuGyNbHgYKFrBs4L7nzsSkcdtejU
and later to Bech32 address
bc1qzzxdvcpp9gk5lkk2zcf2hgz66ml3xasp75ty053094lz80pn52yqrju285