all crypto are ponzi. Look up the definition of a ponzi scheme. its new buyer who support old buyers without any true worth. Cryptos have nothing backpacking them. The dollars has Gold, silver and credit but cryptos on have an idea. They way cryptos buy and sell on an idea make them all a part of a ponzi scheme
You can't have a ponzi scheme unless there's a mechanism for new money to come in, as was the case with Bitconnect. Few cryptos fit this pattern.