Bitcoin dominance and "altcoin season" explained
One number that's quoted everywhere, and the caveats nobody mentions.
Bitcoin dominance is Bitcoin's share of the total crypto market cap: Bitcoin's market cap divided by the market cap of all coins combined. It shows how the market is split, not where it's going. Readings differ between data sites because each counts different coins and most include stablecoins, which pull the number down.
- Ether's share
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- USDT + USDC share
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- Bitcoin dominance without those two stablecoins
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- Total crypto market cap
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Loading CoinGecko's global market data…
How it's calculated
Bitcoin dominance = Bitcoin's market cap ÷ total market cap of all cryptocurrencies × 100
Bitcoin's market cap is its price times the coins in circulation. The total is the sum of the market caps of every coin a data provider tracks. If Bitcoin is worth $1.6 trillion and all crypto together $2.7 trillion, dominance is 1.6 ÷ 2.7 ≈ 59%.
The live figure above comes from CoinGecko's global data. It also shows dominance with the two largest stablecoins taken out of the total, because dollar tokens sitting in the denominator push Bitcoin's share down even though they're not "altcoins" in the usual sense.
Why different sites show different numbers
- Which coins count. CoinGecko tracked about 22,800 coins in November 2026; other providers list different sets and drop different dead or illiquid tokens.
- Stablecoins. Most headline figures include them in the total. As stablecoins grew past $300 billion, that alone pulled dominance down by several points compared with a stablecoin-free measure.
- Supply data. Each provider decides what counts as "circulating" for every coin, and small differences add up.
Even the history depends on the source. CoinGecko describes an all-time low of around 38% at the start of 2018, at the end of the ICO boom; other figures, from data sets that included more small tokens, put the low at about 33% on January 8, 2018. Treat dominance as a rough gauge, and compare like with like from one provider.
What dominance has done
Bitcoin was almost the whole market until 2017; CoinGecko notes dominance was still above 90% when Ethereum launched in 2015. It fell sharply in the 2017 ICO boom, recovered to about 70% in 2019, swung widely between 2019 and 2023, and climbed back above 50% from 2024, the year US spot Bitcoin ETFs launched. These swings reflect new coins being created and money moving between Bitcoin and other coins, not just Bitcoin's own price.
"Altcoin season" and how it's measured
"Altcoin season" is trader slang for a stretch when most other coins rise faster than Bitcoin. The best-known gauge, Blockchaincenter's Altcoin Season Index, defines it precisely: it's altcoin season if 75% of the top 50 coins performed better than Bitcoin over the last 90 days. Stablecoins and asset-backed tokens such as wrapped bitcoin and staked ether are excluded from the 50. The index runs from 0 to 100; on November 5, 2026 it read 41, which the site labels "not altcoin season."
A falling dominance number is sometimes described as altcoin season too, but the two can disagree: dominance falls if stablecoins grow, even when no altcoin is outperforming.
Dominance describes how the market is split today. It isn't a signal of what to buy, and past patterns ("money rotates from Bitcoin to ether to small coins") have played out differently each cycle. Altcoins as a group have also fallen much harder than Bitcoin in every major downturn so far. See what is an altcoin.
Frequently asked questions
What is bitcoin dominance?
Bitcoin's share of the total value of all cryptocurrencies: its market cap divided by the whole crypto market cap.
Why does bitcoin dominance differ between CoinGecko, CoinMarketCap and TradingView?
Each counts a different set of coins and estimates circulating supply its own way, and some figures include stablecoins in the total. Compare readings from the same provider over time.
What is the Altcoin Season Index?
A 0–100 gauge from Blockchaincenter. It calls it altcoin season when at least 75% of the top 50 coins (excluding stablecoins and asset-backed tokens) beat Bitcoin's performance over the past 90 days.
Does falling dominance mean altcoins are rising?
Not necessarily. Dominance can fall because Bitcoin dropped more slowly than the total, because stablecoin supply grew, or because altcoins rose. Check prices, not just the share.
Is bitcoin dominance a buy or sell signal?
No. It's a description of the market's make-up. Nobody can reliably time moves between Bitcoin and other coins with it.
Where to next
Sources
- What is Bitcoin dominance? (CoinGecko)
- CoinGecko API: global crypto market data (/global)
- Altcoin Season Index (Blockchaincenter)
- Bitcoin dominance up 100% since its all-time low (Decrypt)
Written for beginners and checked against the sources listed. Last reviewed November 5, 2026. This page is educational and is not financial, tax or legal advice. How we write and check pages.