Upper limit for the amount of a coin/token which can exist.
Relevant for mineable assets as the total supply/circulating supply numbers will change daily as new coins are mined but the maximum supply will always stay the same. Different coins/tokens have different maximum supplies, and knowing about them is crucial for making wise investments.
The maximum supply for Bitcoin (BTC) and Bitcoin Cash (BCH) is 21,000,000 coins. There will never be more than 21 million in circulation, and the amount of new BCH/BTC mined into circulation will asymptotically approach zero as the rewards for mining decrease over time. The maximum supply is expected to be reached in the year 2140.
* All terms and definitions may update as the Cryptionary improves.