It is somewhat theoretical, as all heavily asset tied wealth is, because if you were to sell all your shares/assets at once, it would devalue it, how much wouldn't be known until you tried to fire sale your assets and learn what the market will bear.
It’s not like he’d log into his etrade account and sell 7853256788943 shares or start selling his physical assets. This is M&A, it’s negotiated and he’d likely get a premium as the buyer would have some strategic interest
but you're saying it would be negotiated, which would mean it's theoretical until those are complete. therefore we can not take todays stock price and multiply it by share count to arrive at net worth.
