Why do sites show different market caps for the same coin?
Compare two or three crypto data sites and the same coin's market cap can differ noticeably, even when the price is almost identical. The difference usually comes down to how each site counts circulating supply.
This guide explains how market cap is calculated, the different definitions of circulating supply, and why locked tokens and dilution matter, using a hypothetical token. It also covers how to cross-check sources and the limits of market cap as a measure.
How market cap is calculated
A coin's market cap is usually price times circulating supply. It resembles a stock's market cap of price times shares outstanding, but while share counts are set out in filings, circulating supply for a token depends on who counts it and how.
As Ethereum.org's page on the ERC-20 standard explains, token contracts expose a total-supply function. That number covers every token in existence; it does not say how many can actually trade. That judgment is made separately by data providers or the project itself.
Comparing circulating-supply definitions
The table shows how three sites might count a hypothetical token with a total supply of 1 billion and a price of $1.
| Category | Tokens | Site A | Site B | Site C |
|---|---|---|---|---|
| Foundation treasury | 300 million | Excluded | Excluded | Included |
| Locked team and investor tokens | 200 million | Excluded | Excluded | Excluded |
| Staked tokens | 150 million | Included | Excluded | Included |
| Other market holdings | 350 million | Included | Included | Included |
| Counted as circulating | - | 500 million | 350 million | 800 million |
| Market cap | - | $500 million | $350 million | $800 million |
Same token, same price, yet market cap ranges from $350 million to $800 million, more than a twofold difference.
Locked tokens and dilution
The 200 million locked team and investor tokens are not counted as circulating today, but they can reach the market once they unlock. Foundation treasury tokens may also trickle out through grants and rewards. Market cap alone shows none of this future supply.
That is why fully diluted valuation (FDV) belongs next to market cap. CoinMarketCap defines FDV as the market cap if the entire maximum supply were in circulation. The wider the gap between the two, the more supply is still to come.
How to treat staked tokens
Staked tokens cannot be sold immediately, but they can return to the market after a withdrawal process. Some sites count them as circulating and some do not. How long withdrawals take, and whether there is a queue, determines how quickly they could affect the market.
Tokens on exchanges raise similar questions. Customer holdings on an exchange are part of circulating supply, but tokens the exchange holds for itself may be different in nature. Where a block explorer labels the owners of large wallets, check those labels too.
In the hypothetical table, whether the 150 million staked tokens count shifts market cap by $150 million. If unstaking takes three weeks, those tokens cannot reach the market quickly, which is an argument for Site B's approach; if it takes a day, Site A's approach is closer to reality.
Common misreadings
"A higher market-cap rank means a bigger coin" compares numbers built on different supply definitions. Tokens with a low circulating share show a smaller market cap and can rank below their true size.
"Market cap is the amount of money invested" is also wrong. Market cap is the last trade price multiplied by the token count; it does not mean that much capital has gone in. For thinly traded coins, a small amount of money can move the price, and the market cap, a long way.
Cross-checking sources
When looking at a coin's market cap, compare several sources.
- Record circulating, total, and maximum supply from two or three data sites side by side.
- Read each site's methodology to see what it includes or excludes: treasury, locked, staked, or burned tokens.
- Compare the sites' figures with the token allocation and unlock schedule in the project's official documents.
- Use a block explorer to check the contract's total supply and the balances of large wallets.
- Look at market cap, FDV, and daily trading volume together to judge liquidity and future supply pressure.
Limits of market cap
Market cap is a starting point for gauging size, not a measure of value. The CFTC warns that virtual currency prices can swing widely with supply and demand, and market cap moves with them.
The supply comparison here uses a hypothetical token. For a real coin, use current data and official documents with their dates, and cross-check several sources against on-chain records rather than relying on one site.