Circulation for Bitcoin has crossed the crucial milestone of 19 million. As of today, 19 million Bitcoins have been mined in totality, inching towards the total supply of 21 million Bitcoins. At the current rate of issuance of 6.25 Bitcoins per block, and factoring in the regular halvings, all 21 million Bitcoins are expected to be mined by the year 2140.
