Max supply is the absolute ceiling on a token's existence. It is typically defined at the protocol level and enforced by the smart contract or consensus rules — no entity can create tokens beyond this limit without changing the core protocol. Bitcoin's 21 million hard cap is the most well-known example: the protocol mathematically guarantees that no more than 21 million BTC will ever be mined. This scarcity guarantee is a fundamental driver of Bitcoin's value proposition. Max supply is distinct from total supply in an important way. Total supply counts tokens that exist right now (minted minus burned). Max supply counts all tokens that could ever exist, including those not yet minted. For Bitcoin, total supply is roughly 19.8 million while max supply is 21 million — the remaining 1.2 million will be mined over the next century through block rewards. For a token like XRP, where all 100 billion tokens were pre-minted at genesis, max supply and total supply started equal, but total supply slowly decreases as transaction fee burns remove tokens permanently. Not all tokens have a max supply. Ethereum, Dogecoin, and many proof-of-stake tokens are designed with perpetual inflation — new tokens are minted indefinitely as staking rewards or block rewards with no hard cap. This creates a challenge for FDV calculations, since FDV = Price × Max Supply has no meaningful answer when max supply is infinite. Tokenomist addresses this by using Year-2035 projected supply for tokens without a max supply. This projection models the expected total supply in 2035 based on the token's emission schedule, giving investors a practical FDV estimate that accounts for a reasonable time horizon rather than producing an infinite or undefined value.