Bitcoin has just reached a historic milestone: 20 million $BTC have been mined.
This means that over 95% of the total supply that will ever exist is already in circulation, leaving less than 1 million bitcoins to be mined in the coming decades.
Due to the halving mechanism, the issuance of new bitcoins is reduced every four years.
As a result, the remaining supply will be mined increasingly slowly — the last $BTC is expected to be mined around the year 2140.
Fun fact: many people say Bitcoin has a limit of 21 million, but this number is actually a rounded figure.
The real mathematical maximum supply is approximately:
20,999,999.9769 $BTC
This happens because mining rewards are repeatedly divided in half over time.
In other words, Bitcoin is one of the few assets in the world with perfectly programmed scarcity.