Please provide proof of bitcoin as a Ponzi scheme! I think you cannot prove it. Bitcoin's main value is as a comparison for central banks on how to improve the efficiency of digital money and save money transfer fees. After all, in Bitcoin trading, there is data available and reflected in charts, so that it allows people to predict future price trends, just like in stock trading. Ponzi schemes do not have this at all, because fraud modes such as Ponzi only rely on money from new members who are more numerous than previous members.