Rarity is a core principle of Bitcoin’s framework. Bitcoin has a hard limit of 21 million coins. As laid out in the design, Bitcoins are mined into existence every 10 minutes, with the number of assets being brought into existence reducing by 50% after every 210,000 blocks. At the end of December 2021, over 18 million coins had already been mined. Therefore, only 14% of the total supply are left to be brought into existence.