"Buy, borrow, die" is simply not a thing. It's a half-baked idea invented by academics, who don't realize that it's just not viable in practice. Billionaires do not actually utilize it[1].

[1] https://www.sciencedirect.com/science/article/abs/pii/S00472...

In that case, isn't the correct analysis how much money is borrowed? If Musk is borrowing $500 million, that won't fund the government very long.

What should probably happen is the gains on any stock used for collateral in a loan are automatically realized for tax purposes.

That would make sense.