Names are hard, because it is common to name something with what looks most like it, even when there are differences. There are two separate phenomena that giv

Names are hard, because it is common to name something with what looks most like it, even when there are differences. There are two separate phenomena that give it the appearance of a Ponzi. First, a Ponzi works by taking the money of new investors, and distributing it to past investors that cash out with “profit”. Similarly, BTC investing (as in, intending to make a profit from the difference between the buy and the sell price) works by taking the money of new investors (in an exchange) and distributing it to past investors that cash out, yielding a profit that, from a systemic perspective, will eventually cause someone’s loss. From that viewpoint, successful investors are unwittingly taking the money of people that may not afford the loss. Second, a Ponzi works by making up assets (typically financial instruments) out of thin air, and selling them to victims (some of which will profit, many will lose), making a profit out of thin air. Similarly, the creator of a cryptocurrency typically puts itself in a position where they either premine the coins, or create an algorithmic schedule where most of the coins are created in the first few years, making them out of thin air, and giving themselves a significant advantage, as they will give themselves a generous chunk. They then sell those coins to victims, making a profit out of thin air. Even Nakamoto famously was flagged as an intensive miner in early years, and clearly did not expect to be deanonymized by the coinbase counter, since they changed it once it was found out. It is true that there are dissimilarities as well. The largest one is the failure mode. A traditional Ponzi fails because people that did not get their “guaranteed profit, whisper past performances is not a guide for future performance”, are unlikely to reinvest, leading to a breaking point where everyone takes their money out until none is left. In the types of cryptocurrencies described above, people are often willing to reinvest even when they lost substantial amounts. The failure mode typically comes many decades later, when lost keys (deaths etc) cause a slow deflation until no coin remains in use.