DCG, the parent of Grayscale got a $600m credit line in 2021, seems like they were deeply under water for quite some time.
It is very possible they dipped into the GBTC fund like FTX did with its user funds.
I made a risky bet in 2019 on GBTC that luckily paid off, but I was 100% willing to lose everything... I keep wanting to try it, but I'd need to be nuts post FTX...