Bitcoin: is it a bubble waiting to burst or a good investment?

Disciples of the cryptocurrency plan to hold on for dear life but traditional finance is getting twitchy

Bitcoin is the fastest-growing asset in the world this year, but the virtual currency does not appear to have many users in London's tech district. It has been more than a month since bitcoin was used to buy a flat white or craft beer sold at the Old Shoreditch Station, according to the hospitality manager at the east London bar.

Bitcoin is the first, and the biggest, "cryptocurrency" - a decentralised tradable digital asset. Whether it's a bad investment is the $97bn question (literally, since that's the current value of all bitcoins in existence). Bitcoin can only be used as a medium of exchange and in practice has been far more important for the dark economy than it has for most legitimate uses. The lack of any central authority makes bitcoin remarkably resilient to censorship, corruption - or regulation. That means it has attracted a range of backers, from libertarian monetarists who enjoy the idea of a currency with no inflation and no central bank, to drug dealers who like the fact that it's hard (but not impossible) to trace a bitcoin transaction back to a physical person.

Related: Everything you wanted to know about bitcoin but were afraid to ask

Related: Bitcoin bubble? The warnings from history