This makes... no sense? You have to pay back the loan on top of the interest, it's not like you got that money for free at a lower tax rate. Whereas if you sell

This makes... no sense? You have to pay back the loan on top of the interest, it's not like you got that money for free at a lower tax rate. Whereas if you sell something the proceeds become yours. How in the world is that a "loophole"? It's not like there's any guarantee you'd end up paying less in interest than if you'd bought bonds or left it in a bank account or something. You're risking your money, whether you make a profit or not isn't guaranteed. That's not a "loophole", that's by-design and a feature that's available to everybody.