Market cap is the price of a token multiplied by the number of tokens in circulation. If there are 10 million tokens outstanding and each one is trading at $5, the market cap is $50 million. The calculation is trivial. What is not trivial is the question of what circulating supply actually means, whether the price reflects the value of buying the whole supply at once, and how much of the reported market cap number you can actually trust.
CoinMarketCap and CoinGecko both display market cap as one of the primary sort fields for rankings, and the crypto industry uses “market cap” as shorthand for “how big is this project” in exactly the same way that the stock market uses market cap to rank companies. The numbers are useful for rough comparisons — Bitcoin’s ~$2 trillion market cap is obviously in a different universe from a memecoin’s $10 million — but they start to get unreliable the moment you dig into any specific token.
Circulating vs Total vs Fully Diluted
For most tokens, three different supply numbers matter. Circulating supply is the amount of tokens currently in public hands and freely tradeable. Total supply is circulating plus tokens that are issued but locked up (team vesting, treasury reserves, unclaimed airdrops). Max supply or fully diluted supply is what the total will eventually be when all vesting is complete and all tokens have been minted.
These three can differ by an order of magnitude. A token can have 10 million circulating and 100 million total supply, with team and investor tokens unlocking over several years. Such a token’s price is being set by demand for the 10 million in circulation, but anybody who bought it thinking “the market cap is $100 million” is wrong — the real number is $1 billion, and the $900 million overhang is going to hit the market gradually as unlocks happen.
Fully diluted market cap (FDV) is a more honest measure for tokens with substantial future unlocks, and the ratio of circulating market cap to FDV tells you how much dilution is coming. If the ratio is 0.10, you are looking at a token where 90 percent of the supply is still locked, and early buyers will be selling into the market over the vesting period, creating sustained selling pressure unless demand grows fast enough to absorb it. If the ratio is 0.90, most of the supply is already unlocked and the dilution risk is smaller.
Why the Number Is Misleading
Price times supply is a calculation, not a valuation. Nobody can actually sell the entire supply at the current price — the order book is not deep enough, and any attempt would crash the price. For Bitcoin, the difference between the quoted market cap and the amount that could actually be realised if everyone tried to sell is substantial but not catastrophic. For a small-cap altcoin with $10 million market cap and $50,000 of daily volume, the quoted market cap is almost entirely fictional; selling 10 percent of the circulating supply would likely drop the price by 50 percent or more.
The honest way to think about market cap for a given token is “this is the price somebody is willing to pay at the margin, multiplied by how many tokens exist”. It tells you the most recent marginal price and the scale of the token in question, but it does not tell you what the total exit value would be if everyone sold at once. The gap between the two can be the difference between a real market and a mirage.
The Manipulation Angle
Because market cap is so prominent in rankings and in media coverage, there is an incentive to game it. A common pattern is to launch a token with a tiny circulating supply, coordinate some initial buying to pump the price, and let the market cap calculation produce a big-sounding number that gets the token listed on CoinMarketCap and covered by crypto media. The “market cap” in this case is a marketing artifact, not a reflection of any real capital committed to the project. Once the supply unlocks later in the vesting schedule, insiders dump into the hyped bid and early retail buyers end up holding the bag.
This is not a theoretical concern. A substantial fraction of the tokens launched in any given cycle follow roughly this playbook, and the “low float, high FDV” structure is now a recognised red flag among more sophisticated buyers. The rule of thumb: if a token has less than 20 percent of its max supply circulating at launch, the FDV is the number you should anchor on, and even then you should expect the price to be overvalued relative to where it will settle post-unlock.