Research · Altcoins · Strand B

ETH and BTC capitalisations compared

Market capitalisation is price multiplied by a supply estimate, and both inputs carry assumptions. This page sets out how the two capitalisations are constructed, what the ratio between them does and does not imply, and why a capitalisation comparison is not a valuation comparison.

Last reviewed 2026-09-21Source: CoinGecko market capitalisation methodologyConstruction and interpretation only. No capitalisation figure is asserted.

How each capitalisation is constructed

A market capitalisation is a price multiplied by a supply figure. The price is observable and the supply is an estimate, and the estimate is where the assumptions live. For Bitcoin, the supply is determined by the issuance schedule and is close to fully observable, with the main uncertainty being how many coins are permanently lost. For Ethereum, the supply is not fixed: it changes with issuance, with the burn introduced by EIP-1559, and with the staking and unstaking of ether. The circulating-supply figure a data provider uses is therefore a modelling choice as well as a measurement.

The two networks also differ in what their supply figures include. Whether staked ether is counted as circulating, how locked or vesting balances are treated, and how the burn is reflected all affect the denominator. Two providers can publish different capitalisation figures for the same asset on the same day without either being wrong, because they made different supply choices. A comparison between two assets is only as sound as the consistency of those choices across the pair.

The site's own treatment of the measure is set out on Market Cap Explained, including where the measure misleads. This page does not restate that material; it applies the same reasoning to a two-asset comparison.

What the ratio does and does not imply

What a change in the ratio of the two capitalisations supports, and what it does not.
Change in the ratio	What it supports	What it does not imply
Ratio rises	The second network's capitalisation grew relative to the first over the window	That capital flowed from one asset to the other; both can grow together
Ratio falls	The first network's capitalisation grew relative to the second	That the second network lost value in absolute terms
Ratio moves with supply	Part of the change may be a supply revision rather than a price move	That the underlying demand changed; the denominator moved
Ratio at a historical extreme	The relative capitalisations are unusual against the chosen history	That either network is over- or under-valued; capitalisation is not a valuation
Ratio stable while prices move	Both capitalisations moved together over the window	That the two networks have equivalent fundamentals

Last reviewed 2026-09-21Source: CoinGecko market capitalisation methodologyThe table separates what each observation supports; no figure is reported.

The most important thing the ratio does not imply is a flow of capital between the two assets. A rising ratio is often described as money rotating from one asset into the other, but the ratio is consistent with both capitalisations rising, with both falling, or with one rising while the other is flat. Rotation is one possible explanation among several, and the ratio alone does not identify it.

The second thing it does not imply is a valuation. Market capitalisation measures the price of the marginal unit multiplied by an estimated supply. It is not a claim about the present value of any future cash flow, because neither network produces one. Treating a capitalisation ratio as a valuation ratio imports an equity-market concept into a setting where its premises do not hold. The Bitcoin Dominance page covers the related question of one asset's share of a total.

Why the supply side matters more here

For a fixed-supply asset, a capitalisation series is essentially a price series with a slowly changing multiplier. For an asset whose supply is managed, the multiplier itself moves, and a capitalisation comparison between the two is partly a comparison of two different supply regimes. Ethereum's supply changes are covered on ETH supply changes in market context, which cites the monetary comparison rather than restating it.

The practical consequence is that a capitalisation ratio should be read alongside the supply series, not instead of it. A ratio move that coincides with a supply revision is partly an accounting change. A ratio move that coincides with a price move is a market change. The two are not distinguishable from the ratio alone.

Dataset, period, method and limitations

Dataset: Daily price and circulating-supply series for ETH and BTC from CoinGecko, with the provider's stated methodology for each supply figure.
Period: From Ethereum's public trading history to the last-reviewed date stated above.
Method: Capitalisation is price multiplied by the provider's circulating-supply estimate. The ratio is computed from the two capitalisation series on each day. Supply revisions are identified from the provider's methodology rather than inferred from the ratio.
Limitations: Circulating supply is an estimate and different providers make different choices about staked, locked and burned balances. A capitalisation ratio is not a valuation ratio. The ratio cannot distinguish a price-driven move from a supply-driven one without the underlying series.

What this page does not claim

This page does not state a capitalisation figure or a ratio level. It does not claim that capital rotated between the two assets, and it does not treat a capitalisation ratio as a valuation. It does not present a historical extreme as evidence about future returns.

Sources and references

Every source below is named and linked. Where a page describes a method rather than a figure, the source is the specification or documentation that defines the method.

Market capitalisation methodology. CoinGecko, www.coingecko.com/en/methodology: how circulating supply and capitalisation are defined and assembled.
Ethereum historical data. CoinGecko, www.coingecko.com/en/coins/ethereum/historical_data: the ETH price and supply series.
Bitcoin historical data. CoinGecko, www.coingecko.com/en/coins/bitcoin/historical_data: the BTC price and supply series.
Market cap explained. Bitcoin Data Guide, bitcoindataguide.com/market-cap-explained: the site's own treatment of what the measure does and does not show.