When you die, your heirs get the stock with "step up basis", meaning the cost basis used to calculate capital gains resets to the market price at time of death. So if they sell right after you die, they pay no capital gains tax.

Heirs in the United States don't pay capital gains tax, but doesn't the estate of the super rich guy have to pay up to 40% in estate taxes on all his assests (with an exemption on the first ~$5M)?

Jeff Bezos is worth $200B. If he died, his estate would have to pay 40% estate tax on $195B in assets (first ~$5M being exempt), which is $78B in tax. That's still a hell of a lot tax. I know there were some loopholes used by the Walton family and other super rich, but isn't the above how it's supposed to work?

> 40% estate tax on $195B in assets (first ~$5M being exempt)

I think you mean $199.995B, but doesn't change the outcome much anyway.

I'm no super genius, but it does sound like simply changing the tax code to require paying back all loans before changing the cost basis would be both easily and less possibly catastrophic than all of a sudden taxing unrealized gains.

The heirs get the stock at etc step-up basis after estate taxes, which are considerable in the $100m+ realm...

Estate taxes can be avoided with trusts.

You die without selling them. Your heirs inherit the stocks at current market value: your capital gain liabilities are not inherited. They sell some stocks to repay the loans. Your gains are never taxed.

More loans.