The bitcoin bubbleThere may be good reasons for buying bitcoin. But the dominant reason at the moment is that it is rising in price By Buttonwood PUT the word Bitcoin into Google and you get (in Britain, at least) four adverts at the top of the list: "Trade Bitcoin with no fees", "Fastest Way to Buy Bitcoin", "Where to Buy Bitcoins" and "Looking to Invest in Bitcoins". Travelling to work on the tu