What if the bitcoin bubble bursts?

MARKETS frequently froth and bubble, but the boom in bitcoin, a digital currency, is extraordinary. Although its price is down from an all-time high of $2,420 on May 24th, it has more than doubled in just two months. Anyone clever or lucky enough to have bought $1,000 of bitcoins in July 2010, when the price stood at $0.05, would now have a stash worth $46m. Other cryptocurrencies have soared, too, giving them a collective market value of about $80bn.