Just put a reasonable threshold on it. Any assets, above $100M, used to collateralize a loan are taxed as if they are realized capital gains at the time that y

Just put a reasonable threshold on it. Any assets, above $100M, used to collateralize a loan are taxed as if they are realized capital gains at the time that you collateralize the loan. I don't think the loan itself should be taxed, but if you use assets to collateralize a loan, those assets should be taxed as if they're realized income—since by taking the loan you are now "realizing" the value of those appreciating assets.