But in October 2009, an Internet exchange2 sold 5,050 bitcoins for $5.02, at a price of $1 for 1,006 bitcoins, to register the first purchase of a bitcoin with money.3 The price was calculated by measuring the value of the electricity needed to produce a bitcoin. In economic terms, this seminal moment was arguably the most significant in bitcoin's life. Bitcoin was no longer just a digital game being played within a fringe community of programmers; it had now become
