OTH, they can do some interesting OTC trades between BIG holders of different assets. And that's exactly what they do when they do want to diversify.
I don't think so. If somebody owned say, CAT the construction equipment company, just vast amounts of physical hardware, buildings, and equipment, the last thing they're going to want for all those real world goods is...some imaginary tokens. Maybe they can trade 200,000 imaginary bitcoins for some imaginary Wall Street company like Facebook, though.
That's your opinion. I am sure there has been trades like those. We (or me) just don't know for sure on the specific ones.
What we know is that people like Richard Branson own significant quantities of BTC. Did they pay in cash or did they traded some other asset? And, any way they did, what's relevant is that they could have just swapped stocks they own in vast quantity with someone that owns BTC in vasts quantities.... "Liquidity problem" solved for big holders.