Future of money or biggest bubble in history?

Cryptocurrencies such as Bitcoin began as an experiment in money that no government or bank controls. Since then they have grown into a large market of coins, exchanges, funds and applications, with enormous price swings. To some people they are the start of a new financial system. To others they are a speculative craze that will end badly.

Supporters make several arguments. They say a digital asset with fixed or predictable supply can protect against inflation and mismanaged currencies, that open networks can move money across borders quickly and cheaply, and that people in unstable countries gain a way to store value outside local banks. They also point to growing use by institutions and in regulated products as a sign of lasting demand [check: verify any current examples you use].

Critics respond that most coins have no cash flow or practical use beyond trading, that prices rise on belief and fall when belief fades, and that the history of the sector includes fraud, collapsed exchanges and large losses for ordinary people. They also raise energy use for some networks, links to crime, and the point that daily payments are mostly made with stable, regulated money and not volatile coins.

There are also different questions in the same debate: whether a currency like Bitcoin can work as money, whether technology like blockchains has other uses, and whether prices are too high. A person can believe the technology is useful and still think many assets are overvalued.

It also helps to remember that this market moves quickly. Facts, prices and rules change from month to month, so a claim that was true last year may not hold now, and good arguments say when their evidence is from.

If you take part in this debate, it helps to say which assets you mean, whether you mean money, investment or technology, and what event or measure would change your mind.