What is Max Supply?
How it works
The max supply is defined at the protocol level, typically in the genesis block or initial code. For Bitcoin, the max supply is 21 million BTC, enforced by the block reward halving mechanism every 210,000 blocks. The code rejects any transaction that would create coins beyond this cap. This is a fixed, transparent rule that all network participants can verify.
Other protocols use different approaches. Ethereum does not have a hard max supply, but its monetary policy is governed by EIP-1559 and proof-of-stake issuance. Tokens like BNB originally had a 200 million max supply, with periodic burns reducing the circulating supply. The max supply is often recorded in the token contract (e.g., ERC-20 standard) and can be audited on-chain.
Max supply differs from circulating supply (coins currently available) and total supply (minted minus burned). Once the max supply is reached, no new coins can be mined or minted. This creates a deflationary or fixed-supply asset, contrasting with fiat currencies that central banks can print indefinitely.
Why it matters
Max supply is fundamental to a cryptocurrency's monetary policy and value proposition. A fixed or capped supply creates digital scarcity, which can support long-term value preservation and protect against inflation. It enables predictable issuance schedules, helping investors and users understand future dilution. For proof-of-work coins like Bitcoin, the cap ensures that mining rewards eventually transition to transaction fees. Without a max supply, a token risks unlimited inflation, potentially undermining trust and utility.
Real-world examples
Bitcoin's max supply is 21 million BTC, a cap set by Satoshi Nakamoto. Litecoin has a max supply of 84 million LTC. BNB initially had 200 million tokens, with quarterly burns reducing the total. Many ERC-20 tokens like Chainlink (LINK) have a 1 billion max supply. In contrast, Ether (ETH) has no hard cap, though its supply growth is limited by proof-of-stake issuance.
FAQ
Can a cryptocurrency's max supply be changed?
Changing the max supply requires a hard fork of the protocol, meaning all nodes must upgrade to new software. This is extremely difficult for established networks like Bitcoin because it would break consensus with existing users.
What happens when max supply is reached?
When max supply is reached, no new coins can be mined or minted. Miners or validators then earn only transaction fees as rewards. The network continues to operate normally, but the total supply becomes fixed.
Is max supply the same as total supply?
No. Total supply includes all coins that have been minted, minus any that have been burned. Max supply is the absolute cap that can ever exist. Circulating supply is the subset of total supply currently available to the public.
Related terms
Go deeper
Browse the complete crypto glossary to explore related terms and concepts.
Browse Glossary