Earlier quoted context omitted.
> funded by some of the initial LUNA tokens. Which were bought by users in a zero sum-game. A ponzi is a zero-sum game where new entrants finance old exits. Just because the funding for the ponzi is done in a different currency doesn't mean it's not one. You can't create a closed system that generates wealth, and when you're growth hacking with your users' money, you are running a fraud.
Anchor protocol always retained the full amount of each UST deposit, plus additional rewards (whose funding was external to Anchor), so clearly Anchor is not a Ponzi, as I thought you were implying originally. Would you assert that any undercollateralized currency is a Ponzi? (Seems like stretching the definition to me.) Or that any system with unsustainable rewards is a Ponzi, even if there was no expectation that t…
This was the major innovation of UST. A ponzi that's sufficiently obfuscated that if you look at any part of the system in isolation, it seems fine.
You can have an uncollateralized currency - like baseball cards, but that's not what UST was. It made additional promices (like being a stablecoin, and offering yield).
You maybe even theoretically can create an uncollateralized stablecoin (that remains stable) but you're not going to attract $XY billion into your stablecoin without dangling a carrot to convince the greedy to invest. Investing into a stablecoin is stupid[1], because its price can't go up - so in this case, the carrot was fraudulent yield.
UST only had value because it was backed by Luna, and it only had demand for it because of the promises of yield. Luna was backed by nothing but speculation, driven by demand for UST. Once net money stopped flowing into the Luna ecosystem, the whole thing collapsed.
Any system that only works as long as net value flows into it, but produces no value of its own, but promises yields is a ponzi.
[1] Yes, there are use cases for it that don't involve speculation, but those use cases aren't going to see the market cap explode at the rate Tera/Luna did.