I wonder who is handling the custody of this for them. That was probably the hardest part of the whole thing for them to work out.
I figure it could be Greyscale, or one of the exchanges (Gemini? Kraken? Coinbase?). Could be Bakkt? Of course they could do it themselves, but that is a fairly serious security undertaking when $250MM is the amount of value.
If it's actual coin then one of your list no doubt. I'd love to sit in on the pitch these custody places give them. A lot of people will come to them knowing nothing and nothing about their specific company either. There's no question of any of it being insured either. It likely never will be.