Dad buys 5 BTC in 2019 for $35,000. It grows to $380,000. If he sells, he owes capital gains tax on $345,000 of appreciation. Instead, he takes out a Bitcoin-backed loan. Borrows $60,000 a year to live on. Pays the interest. Keeps every sat. Dies holding all 5 BTC. Kids inherit at a $380,000 stepped-up basis. IRS gets $0. $BTC