> to actually do anything with that paper wealth, he needs to sell the stock or engage in a similar realization event, in which case that gain will be taxed Th

> to actually do anything with that paper wealth, he needs to sell the stock or engage in a similar realization event, in which case that gain will be taxed The ProPublica analysis that the BBC refers to [1] explains it: you borrow with the capital as collateral and then when you die the debt is repaid by selling some of the capital. But because of the stepped-up basis on death there is never a "realization" of positive gains. [1] https://www.propublica.org/article/the-secret-irs-files-trove-of-never-before-seen-records-reveal-how-the-wealthiest-avoid-income-tax https://www.propublica.org/article/the-secret-irs-files-trov...