cryptoknowmics.com
More than 90% of the total amount of Bitcoin (BTC) available for mining has already been mined. A supply shock may become unavoidable if the monetary network expands in popularity and applications throughout the world, raising demand for BTC.
The Bitcoin network, the only form of digital money that addresses the double-spending problem in a properly distributed and trustless way, imposes a supply ceiling of 21 million coins through its consensus mechanism controlled by tens of thousands of nodes throughout the world.
Bitcoin's steady and constant monetary policy is one of its most appealing features, especially when compared to the reality of fiat and "crypto" currencies, whose supply and monetary policy can change based on the actions of a few people.