I remember being very early and I have been in this bitcoin space for over 6 years now and they were even earlier than me.
They got in like at 40 dollars each bitcoin and they once said they had like 1% of all bitcoins and that means it was about 40 thousand bitcoins back than, now of course that must have dropped a lot but still considering they have over 40 thousand bitcoins and one bitcoin is about $7k (even went as high as $20k each) they worth over 280 million dollars as it is already, and this is just assuming they have 40 thousand bitcoins, it could be way over and even if it is $40k at one point when bitcoin was $20k, they had like 800 million dollar worth of bitcoins. WOW.
I know these guys started an exchange in 2013 but closed it in 2017. Maybe they managed to increase their bitcoin assets through commissions they got from people trading there.