Is This The Hackers Bitcoin Account?
As you can see, looking on Bitinfocharts, this account had nothing in yesterday and now today it has over $65M USD. Somewhat of a coincidence when all of NiceHash's Bitcoin goes missing. You can see the details in this link:
https://bitinfocharts.com/bitcoin/address/1EnJHhq8Jq8vDuZA5ahVh6H4t6jh1mB4rq
Makes you wonder. Of course, because of the nature of any cryptocurrency, we may see how much they've stolen, in fact it could be just some random rich account, or it could be the hacker. Either way, we will never know who or where they are, just that someone, somewhere, has now an awful lot of money.