Rich people get access to astonishingly favorable loans. And they never have to make interest payments.

> Merrill Lynch recently quoted an interest rate of 3.2% to clients with at least $1 million in assets. Those with $100 million or more can get a rate as low as 0.87%.

These are loss leaders for banks. They want to entice incredibly wealthy people to do business with them and have their companies do business with them.

Wealthfront has a product for the merely rich: https://www.wealthfront.com/portfolio-line-of-credit

> Because your line of credit is secured by your diversified investment portfolio, we can keep the rates low for you. Depending on account size, current rates are 2.40% - 3.65%. Using a line of credit is generally cheaper than carrying a balance on a credit card or taking out a personal loan.

> Borrow up to 30% of your account whenever you need it, for whatever you need. Pay back what you borrow and the interest payment on your own schedule.

The rich invest in hard assets that produce income. Whether that's dividend from stocks, or rental income from commercial buildings. That recurring income is usually enough to service the loan.

And remember the ultra-rich themselves own the bank. Warren Buffet has huge multi-billion dollar positions in Goldman Sachs and Wells Fargo, in addition to owning the real-estate arm of Berkshire Hathaway itself. And the ones that don't own the banks, still get favorable personal treatment from banks in order to get their M&A or underwriting business.