As of Monday morning, 90% of the total bitcoin supply of 21 million has been mined, according to data from Blockchain.com.
The remainder is not expected to be mined until February 2140. Until then, miners can continue to earn bitcoins.
Bitcoin operates on a proof-of-work model, which means that miners must compete to solve complex math problems to validate transactions. It’s not an easy process — reaching the 90% milestone took 12 years.