In my opinion it is a scheme where somebody promises big profits to investors, and actually pays these profits to investors by using the money from other investors, keeping a big slice for himself. It can only work by getting ever more investors, which means that ever more money has to be found to pay back, so it has to collapse.
i'm not sure how that doesn't describe bitcoin. without new investors, the price collapses. that's the whole problem, there's nothing productive happening with the investment. when you say the price rises with demand and no other mechanism, which is why i asked several times hoping for a different answer, that's exactly what that means.
you might say, oh well there's no central authority promising big profits to investors. and while that is perhaps true, but i think that since the concept of bitcoin changed from an alternative currency to an "investment" (and part of the problem with this discussion is this thing changes from a currency to an investment to a store of value to a hedge against inflation and back and forth when convenient), since it flopped as a currency, that's all anyone in the space has been promising and there's absolutely a handful of people with significant holdings behind that.
www.fool.com
look at a guy like michael saylor, who is using bitcoin as a ponzi scheme for a stock where he sells you shares of bitcoin and uses that profit to inflate the price of bitcoin. it's a ponzi within a ponzi. do we even have to talk about all the alt coins, which use bitcoins basic framework to create a million scams? thousands of those have collapsed since they were made, bitcoin isn't guaranteed to last forever.
hey, what happens when it's too expensive to mine and the transactions slow? do the whales all find their exit liquidity and everyone is left holding the bag? isn't that how a ponzi functions? the differences are very small imo
but in the meantime, you get a non-stop series of scams, and child molesters and terrorists get to launder their money while the greediest people on earth get a 5% fee and we waste a ton of electricity. i guess ponzis don't typically do that.