The intrinisc values of his companies, and others, are a fraction of their current market value.
When you borrow against it, when the price falls back to intrinsic value, in Musk's case 1/100th or so of Tesla's current valuation, they get margin calls.
My point is not hard to understand and undeniably true. Owning theoretical money you can't realize in full is not the same as owning assets that can be realized. Musk is not trillionaire, never was.