I like interest free loans, too! I feel like the services that tout tax-loss harvesting don't do a clear job of explaining that it's only interest free loan if

I like interest free loans, too! I feel like the services that tout tax-loss harvesting don't do a clear job of explaining that it's only interest free loan if your future tax bracket is the same. For example, if you're going to be moving to a different state after the tax losses are harvested—say, from MA to CA—then that "interest free" loan will cost you ~5% (the difference in tax rates between those states). Or, if you're just starting out in your career, and you're going to be in a higher tax bracket in a few years—about the same time that many would start looking at buying real estate—then it's again a cost equal to the delta in marginal tax rates (say, 3% or 8%, depending on how your starting salary compares with your salary 5 years into your career). I'd love if Vanguard got into this market as well; although it seems like they already are, with their target date index funds. Admittedly, no tax-loss harvesting, if that's important to you.