StableGains is just a thin layer on top of Anchor. See https://blog.stablegains.com/stablegains-earns-you-yield-by-...

I'm not OP, but the money has to come from somewhere, because people want dollars, not some $shitcoin which may drop 90% in value overnight.

A credit card typically maybe has 15-19% interest. So I'd be surprised if the average credit card gets 10% profit per year from interest payments minus defaults. But somehow you're going to get a guaranteed 15% rate from algorithms? Smart contracts?