Billionaires like Larry Ellison and Elon Musk borrow huge sums of money to support their lifestyle, pledging their stock as collateral. This borrowing is entirely tax-free and comes at good rates. In addition, in recent years the growth in stock value more than compensatesfor any interest that might accrue. To pay the interest and pay back the loans, [they simply borrow again](https://www.sciencedirect.com/science/article/abs/pii/S0047272725002178?vi).