Definition
Max supply is the largest number of coins or tokens that can ever exist for a cryptocurrency, as set by its protocol rules. Once it is reached, no new units can be created.
How it works
Many cryptocurrencies write a hard cap into their code. Bitcoin is the best-known case: its rules allow at most 21,000,000 bitcoin, and new coins are released on a fixed schedule that slows down over time through the halving. Other projects create their full max supply at launch and release it gradually through vesting and unlock schedules, so total supply reaches the cap long before circulating supply does.
Not every network has a maximum. Ethereum, for example, has no fixed cap: new coins are issued continuously as rewards while part of the fees is burned, and whether supply rises or falls over a period depends on the balance between the two. For coins like this, the max supply field on data sites is typically left blank or marked as unlimited.
Max supply is used to judge future dilution, because the gap between today's circulating supply and the cap is the amount still to come. It is also the input for fully diluted valuation. A cap is only as firm as the rules behind it: in some projects, governance votes or contract upgrades can change the max supply, so it is worth checking who has that power. A cap also does not create value by itself; demand still sets the price.
Example (hypothetical numbers)
Suppose Coin Y has a max supply of 100,000,000 coins and 64,000,000 have been issued so far.
Coins still to be issued = 100,000,000 − 64,000,000 = 36,000,000, so 64% of the cap is already out.
Future issuance compared with today's supply = 36,000,000 ÷ 64,000,000 = 56.25%.
A hard cap limits the final supply, but holders can still see supply grow by more than half before the cap is reached.
Common mistakes
- Assuming a capped coin will not see much more supply, when a large share may still be unissued.
- Believing every cryptocurrency has a max supply, when some networks issue new coins with no end date.
- Treating a hard cap as permanent in projects where governance or upgrades can change it.
- Thinking a fixed max supply alone guarantees that the price will rise.
Related calculators
This glossary is for education only and is not investment advice. Examples use hypothetical numbers.