Direct Answer
Altcoin market cap ex-BTC and ETH is total cryptocurrency market capitalization minus Bitcoin's market cap and minus Ethereum's market cap, leaving the combined dollar value of every other coin and token. It is used to gauge the size and trend of the broader altcoin market without the distortion of the two largest assets, which can each individually move total market cap by trillions of dollars on their own.
Key Takeaways
- Altcoin market cap ex-BTC and ETH = Total crypto market cap − Bitcoin market cap − Ethereum market cap.
- It is a dollar figure, not a ratio - it does not by itself say what share of the market altcoins represent.
- Some charting platforms label this series "Total 3" (total market cap minus the top two assets); "Total 2" refers to total market cap minus Bitcoin alone.
- Rising altcoin market cap ex-BTC and ETH alongside falling Bitcoin dominance is one loose signal traders associate with "altcoin season," though no single indicator defines that term precisely.
- The figure depends heavily on which coins and tokens a given data provider counts, including how it handles stablecoins and wrapped assets.
- It can decline even while individual altcoins rally, if Bitcoin or Ethereum are rallying faster and pulling a larger share of new capital.
- It is a market-wide aggregate, not a signal about any specific altcoin's fundamentals or price action.
- Because it aggregates thousands of assets of wildly different liquidity and quality, large moves in a handful of megacap altcoins can dominate the whole series.
How Is Altcoin Market Cap ex-BTC and ETH Calculated?
The calculation is a straightforward subtraction:
Altcoin Market Cap (ex-BTC, ex-ETH) = Total Crypto Market Cap − Bitcoin Market Cap − Ethereum Market Cap
Total crypto market cap is the sum of circulating-supply market caps across every coin and token a given data provider tracks (circulating supply multiplied by current price, summed across assets). Bitcoin market cap and Ethereum market cap are each calculated the same way for those two assets individually. Subtracting both from the total isolates the combined value of the rest of the market - everything from large-cap layer-1 blockchains and DeFi tokens down to small-cap and micro-cap coins.
Data aggregators differ in exactly which assets they include in "total market cap" (some exclude certain stablecoins, wrapped tokens, or exchange-only tokens), so the precise ex-BTC-and-ETH figure can vary slightly from one source to another even at the same moment. The trend and relative magnitude matter more than treating any single provider's number as an exact, universally agreed figure.
A Hypothetical Illustration
Consider a hypothetical snapshot where total crypto market cap is $2.5 trillion, Bitcoin's market cap is $1.2 trillion, and Ethereum's market cap is $400 billion. Altcoin market cap ex-BTC and ETH would be $2.5 trillion − $1.2 trillion − $400 billion = $900 billion. That $900 billion figure represents the combined value of every other coin and token in this hypothetical scenario - none of these numbers are real market data, only an example of the arithmetic.
Now imagine that a month later, total market cap has grown to $2.7 trillion, but Bitcoin alone accounts for $1.5 trillion of that growth while Ethereum stays roughly flat at $400 billion. The ex-BTC-and-ETH figure would then be $2.7 trillion − $1.5 trillion − $400 billion = $800 billion - a decline, even though total market cap grew, because Bitcoin captured a disproportionate share of the new capital. This illustrates why the ex-BTC-and-ETH figure and total market cap can move in opposite directions.
Why This Metric Matters
Bitcoin and Ethereum together frequently represent a majority of total crypto market cap, which means headline "total crypto market cap" figures can move mostly because of price action in just two assets. A trader trying to gauge sentiment or capital flow toward the broader altcoin market - the thousands of other projects - gets a distorted picture from the total-market-cap number alone. Isolating the ex-BTC-and-ETH figure gives a more direct read on that segment specifically.
This metric is also commonly paired with Bitcoin dominance (Bitcoin's market cap as a percentage of the total) to describe market rotation. When Bitcoin dominance falls and the ex-BTC-and-ETH dollar figure rises at the same time, that combination is often read as capital rotating out of Bitcoin and into the broader altcoin market. When both move together in the same direction, it suggests the whole market - not any specific segment - is driving the change. Neither reading is a precise trading signal on its own; both are directional context.
Limitations and Common Mistakes
- Provider methodology differences. Which coins count toward "total market cap," and how stablecoins or wrapped tokens are treated, varies by aggregator - figures from different sources are not perfectly comparable.
- Treating it as a tradable index. There is no single fund or product that tracks this exact figure; it is a descriptive aggregate, not an investable instrument, and cannot be bought or sold directly.
- Ignoring concentration within the aggregate. A handful of large-cap altcoins can dominate the ex-BTC-and-ETH figure, so a rising total does not mean broad-based strength across thousands of smaller assets.
- Confusing it with a percentage. It is a dollar amount, not Bitcoin or Ethereum dominance - a rising dollar figure does not automatically mean altcoins are gaining market share if total market cap is rising even faster.
- Reading short-term noise as a trend. Like any market-cap aggregate. It is exposed to the same volatility, low-liquidity price swings, and data lags that affect individual crypto assets, so single-day moves carry limited signal.
- Overweighting it as a standalone signal. "Altcoin season" and market-rotation narratives built on this figure alone ignore other relevant context like trading volume, on-chain activity, and macro conditions.
Frequently Asked Questions
What does 'altcoin market cap ex-BTC and ETH' mean?
It refers to the combined market capitalization of every cryptocurrency other than Bitcoin and Ethereum. It is calculated by taking the total crypto market cap across all tracked coins and subtracting Bitcoin's market cap and Ethereum's market cap, leaving the value attributable to the rest of the market.
Why exclude both Bitcoin and Ethereum instead of just Bitcoin?
Bitcoin and Ethereum together typically represent a large share of total crypto market cap, and Ethereum's size can dominate an 'altcoin' aggregate almost as much as Bitcoin does. Excluding both isolates the smaller-cap altcoin segment more cleanly than excluding Bitcoin alone, which is why this metric is sometimes labeled 'Total 3' on charting platforms.
How is this different from Bitcoin dominance?
Bitcoin dominance is a percentage - Bitcoin's market cap divided by total crypto market cap. Altcoin market cap ex-BTC and ETH is a dollar figure, not a ratio, representing the absolute value of the non-BTC, non-ETH segment. The two can move independently: dominance can fall while the ex-BTC-and-ETH dollar figure still declines, if the entire market is shrinking faster than Bitcoin's share of it.
Where can I find the current altcoin market cap ex-BTC and ETH figure?
Aggregators such as CoinMarketCap and CoinGecko publish total crypto market cap alongside individual coin market caps, and several charting platforms track this specific subtracted series directly (often labeled 'Total 3' or 'Others'). Because methodologies for which coins are included and how supply is counted differ slightly between providers, the exact figure can vary by source.
How does excluding Ethereum change what this measure is sensitive to?
It removes the second largest component, which leaves a series driven by a much larger number of much smaller assets. That has two effects. The measure becomes more responsive to broad moves across smaller tokens instead of being dominated by one asset's price. It also becomes noisier, because the remaining set contains assets with thinner liquidity and less reliable supply data, so a data error or a single large token's supply change moves the total more visibly than it would in a measure that still included Ethereum.
Should stablecoins be excluded from this measure as well?
Many readers assume they already are, and often they are not. Stablecoins hold a large aggregate market capitalisation that is roughly flat in price and changes mainly through issuance and redemption. Leaving them in means the series moves when stablecoin supply grows even though no altcoin repriced. Excluding them produces a cleaner read on altcoin valuation but discards a genuine signal about capital sitting ready to deploy. Neither choice is wrong, and the provider's methodology page is where to find which one was made.
Can this measure rise while most altcoins fall?
Yes, because it is capitalisation weighted. A handful of the largest remaining tokens carry enough weight to lift the total while the long tail declines. That is the same arithmetic that lets a capitalisation weighted equity index rise on a day when most of its constituents fall. Anyone using this series as a proxy for how a broad basket of altcoins is doing should pair it with a breadth measure, such as the share of tracked assets that gained, rather than treating one number as describing the whole set.
How is this different from an equal weighted altcoin index?
This measure sums market capitalisations, so each asset contributes in proportion to its size and the largest few dominate. An equal weighted index gives every constituent the same influence regardless of size, so it reflects the typical altcoin rather than the largest ones. The two can move in opposite directions during a period when large tokens outperform small ones or the reverse. Choosing between them is choosing between measuring the total value of a sector and measuring the experience of an average asset in it.
Does adding or removing assets from the tracked universe move this figure?
Yes, and the movement has nothing to do with price. A provider that begins tracking a large previously uncovered token adds its entire capitalisation to the total in a single step, and delisting one removes it the same way. Because coverage decisions are made by the provider rather than announced as index changes, these steps can appear in a chart as a jump with no market explanation. Comparing the series across a long window means checking whether the coverage universe was consistent over it.
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Disclaimer
This content is for educational purposes only and does not constitute investment, financial, tax, or legal advice. Swoopr Investment does not recommend any specific cryptocurrency or trading strategy. Market-cap aggregates like the ex-BTC-and-ETH figure are descriptive statistics, not predictive indicators, and should not be used in isolation to make investment decisions. Cryptocurrency markets are highly volatile and carry substantial risk of loss. See our Financial Disclaimer for more information.