With few uses to anchor their value, and little in the way of regulation, cryptocurrencies have instead become a focus for speculation, The Economist magazine said this week.
From the story, which may be paywalled: Some people have made fortunes as cryptocurrency prices have zoomed and dived; many early punters have cashed out. Others have lost money. It seems unlikely that this latest boom-bust cycle will be the last.
Is Bitcoin Valuable?
Economists define a currency as something that can be at once a medium of exchange, a store of value and a unit of account. Lack of adoption and loads of volatility mean that cryptocurrencies satisfy none of those criteria.
That does not mean they are going to go away (though scrutiny from regulators concerned about the fraud and sharp practice that is rife in the industry may dampen excitement in future). But as things stand there is little reason to think that cryptocurrencies will remain more than an overcomplicated, untrustworthy casino.
Can blockchains -- the underlying technology that powers cryptocurrencies -- do better?
These are best thought of as an idiosyncratic form of database, in which records are copied among all the system's users rather than maintained by a central authority, and where entries cannot be altered once written.
Proponents believe these features can help solve all sorts of problems, from streamlining bank payments and guaranteeing the provenance of medicines to securing property rights and providing unforgeable identity documents for refugees.
Those are big claims.
Many are made by cryptocurrency speculators, who hope that stoking excitement around blockchains will boost the value of their related cryptocurrency holdings.