Application

Inventory peaked on 13 March 2011 with 2,593,051 bitcoins. It had rapidly been rising from 2009 to 2010 because it was easy to mine bitcoins and there was not much to do with them at the time. But as application and interest grew, so did the demand for bitcoin. The miners then sold those bitcoins to new buyers, decreasing their inventories, meaning the coins were now first spent.

As alluded to in the example above, a rising first spend likely signals a favourable market bid for sellers.