Dominance is crypto's internal risk gauge. In selloffs, altcoins usually fall harder than bitcoin, so bitcoin's share rises passively — money hiding in the biggest, oldest asset. In speculative phases the reverse happens: capital rotates down the risk curve into smaller tokens ("altseason") and dominance bleeds. The ratio peaked near 100% before altcoins existed, bottomed in the 30s during 2017-18 and 2021 manias, and has spent 2026 in the mid-50s while sentiment sat in
extreme fear.
One trap: the number depends on who's counting. Every tracker uses the same numerator — bitcoin's market cap — but different denominators, disagreeing on which tokens qualify and whether stablecoins count. The same day
read 56.3% on CoinMarketCap and about 60% on Coinbase. Watch the trend on one source, not the level across sources.