> Ponzi schemes by definition use opaque ledgers.

Why? To me a ponzi scheme is where the earlier "investors" get paid out with the money of later "investors". That's it. By that definition it's quite the "decentralized", somewhat stochastic ponzi.

Ponzi victims are told on paper that their "investments" are increasing in value, and that they can withdraw at any time, when in reality, the assets don't actually exist. Also a key aspect is that their balance only ever goes up.

your definition includes stocks. I suppose you might be right that stocks are a ponzi

they weren't back when the reason people bought them were dividends, now the only real exit is if the company goes bankrupt or is purchased. The intervening time is hard to describe as anything other than pure speculation and piling dupes on top of each other

Your definition covers every investable asset.