Why two market caps are not always comparable

Market capitalisation is the default way assets get ranked, which encourages reading it as a standardised measure of size. It is price multiplied by circulating supply, and both of those inputs are less solid than the resulting number looks.

The price is a last trade, not a valuation

The price in a market cap calculation is whatever the most recent trades cleared at, usually aggregated across venues. It reflects the marginal buyer and seller — the small proportion of supply that changed hands — not what the whole supply could be sold for.

This matters more as liquidity thins. For an asset where a large share of supply trades regularly, the last price is a reasonable estimate of what more of it would fetch. For one where a tiny fraction trades, the last price can be set by a small amount of money and the market cap extrapolates it across the entire supply.

Two assets showing the same capitalisation can therefore represent very different amounts of capital actually committed.

The supply figure is a convention

The second input carries its own uncertainty. Circulating supply excludes tokens deemed unavailable, and what counts as unavailable is a judgement rather than a measurement — which is why providers publish different figures for the same asset.

The largest disagreement concerns tokens held by a foundation or treasury under a stated but unenforceable commitment. Include them and the capitalisation rises; exclude them and it falls. Neither treatment is wrong, and the choice is rarely stated where the number is displayed. Our explainer on the three supply figures covers the definitions.

What the number does not measure

Several intuitions attach to market capitalisation that it does not support:

• Money invested. Capitalisation is not the sum of what people paid. It is the current price applied to all units, most of which were never bought at that price.
• Realisable value. Selling the supply would move the price long before the sale completed. The figure is what the supply is notionally worth, not what it could be exchanged for.
• Adoption or usage. Price reflects what buyers will pay, which can diverge from any measure of use for extended periods.

Comparing across designs

Comparability degrades further between assets with different structures. An asset with fixed supply, one with ongoing issuance, and one with a large locked allocation are three different economic objects, and one number does not put them on a common footing.

Comparing fully diluted valuations helps with the third case and introduces its own distortion, since it prices tokens that may not exist for years as though they existed now. Neither figure is complete, which argues for looking at both and at the gap between them.

Where it is genuinely useful

None of this makes market cap useless. Used carefully it does two jobs well.

It gives a rough ordering. The distinction between an asset in the top ten and one in the top thousand is real and survives every caveat above. And it corrects the unit-price illusion, which is its most valuable function: it demonstrates why an asset priced at a fraction of a cent is not therefore cheap, because unit price is capitalisation divided by a supply that may be enormous. Our market cap what-if tool makes the arithmetic concrete.

How to read a figure honestly

Check which supply definition the source used, look at traded volume relative to capitalisation as a rough liquidity check, and look at the gap between circulating and fully diluted figures. Then treat the result as an approximate ordering rather than a measurement.

That is a less satisfying position than a leaderboard implies, and it is the accurate one. We show the provider and timestamp beside every figure on this site for the same reason: a number without its provenance invites more confidence than it has earned.

Volume relative to capitalisation as a rough check

Since the reliability of a market cap depends heavily on how much of the supply actually trades, a crude ratio helps: daily traded volume divided by capitalisation.

A high ratio suggests the price is set by meaningful activity. A very low one suggests the last price is doing a great deal of extrapolation across a supply that rarely moves. This does not produce a threshold — there is no line above which a figure becomes trustworthy — but comparing two assets on this ratio is more informative than comparing their capitalisations alone.

The caveat is that reported volume is itself among the least reliable figures in the sector, aggregated across venues of very uneven quality. We pass through what the provider reports and name the provider rather than applying a silent correction, which is the same policy we apply to every other figure.

Dominance shares inherit every problem

Dominance — one asset’s capitalisation as a share of the total — is widely quoted and compounds the issues above rather than avoiding them.

Both the numerator and the denominator depend on supply conventions, and the denominator depends additionally on which assets are included in “the total”. Providers differ on whether to include stablecoins, wrapped assets, and tokens whose supply is largely locked. Including wrapped versions of an asset alongside the asset itself double-counts the same underlying value.

Dominance is therefore best read as a rough directional indicator over time from a single consistent source, and not as a precise figure comparable between providers.

The practical position

Market capitalisation is a useful ordering and a poor measurement. Treated as the former it corrects a genuine and widespread error about unit prices. Treated as the latter it invites conclusions its inputs cannot support.

The distinction is not pedantry. Most of the confident claims about an asset being “bigger than” some conventional company rest on reading a rough ordering as a precise measurement — and the two inputs, a marginal price and a conventional supply figure, are exactly where that reading breaks.