No it's that billionaires mostly aren't worth their estimated net worth in actual cash.
If Elon Musk wanted to turn his Tesla holdings into cash, then his estimated net worth of $436 billion dollars would very rapidly not be worth anywhere near that much (i.e. probably by at least an order of magnitude).
Are you claiming TSLA is fundamentally worth less than $43.6B, and the mere fact that Elon owns 23% of TSLA shares is worth four hundred billion dollars?
I know that selling 23% of a company in one go would move the market, but a 90% haircut would be bonkers.
Or are you claiming TSLA is special, and the haircut would be 90% just for Elon and just for TSLA because that particular stock is super overvalued due to his celebrity and reality distortion field? That seems a little more believable, but this was a discussion on net worth of generic billionaires to start.
If Elon Musk wanted to turn his Tesla holdings into cash, then his estimated net worth of $436 billion dollars would very rapidly not be worth anywhere near that much (i.e. probably by at least an order of magnitude).