Maximum Supply
The largest number of units that can ever exist, for assets whose rules impose a hard limit.
Bitcoin is the standard example: the block subsidy halves every 210,000 blocks, and the resulting geometric series converges below 21 million units, a limit every node enforces by rejecting blocks that pay more. Many assets have no cap at all, including Ethereum, whose issuance follows a rule tied to how much is staked rather than a terminal total. For tokens, a stated maximum lives in contract code and is only as durable as that contract's mint permissions and upgrade path. Data providers therefore show maximum supply as a number, as unlimited, or as unavailable, and the distinction matters when computing fully diluted valuation.
In practice
Bitcoin's limit is not a policy statement: it follows from the halving schedule that every node independently checks when validating a block's reward.
The common misunderstanding
A stated maximum supply is only as strong as whatever enforces it; a contract with an owner who can mint has a marketing figure, while a consensus-enforced schedule has a real one.
The figure this maps to
The largest number of tokens that can ever exist, where the code actually enforces a limit.
Limits: A maximum is only real if the code enforces it and the code cannot easily be changed; many published maximums come from a whitepaper or token-sale document and could be revised by a governance vote or a protocol upgrade. Assets with genuinely unbounded issuance, including Ethereum after its 2022…