Bitcoin dominance: one number, hard to argue with

The definition

Bitcoin dominance = Bitcoin's market cap ÷ total crypto market cap × 100

Market cap is price times circulating supply. Add up every listed coin's market cap, see what fraction of that pile is Bitcoin, and you have dominance. It is the crypto market's market-share chart, with one company on it.

What moves it

Dominance rises when Bitcoin outperforms the rest of the market — in a rally it leads, or in a sell-off it falls less. It drops when money rotates outward into altcoins, which is why traders watch it as a rotation gauge: falling dominance has historically accompanied the stretches people call “altseason”. Historically accompanied is not a promise; the gauge describes where money has been, not where it is going.

The distortions worth knowing about

The denominator is not a clean number. Stablecoins sit inside the total market cap even though nobody expects Tether to rally, so tens of billions of parked dollars quietly push dominance down without any altcoin doing anything. New listings add to the total the day they appear. And coins with a large locked or unreleased supply are counted by circulating figures that data providers estimate differently.

None of that makes the number useless — it makes precision theatre. Whether dominance is 59% or 61% matters less than whether it has spent three months rising or falling.

How AltClock shows it

The Reality view puts Bitcoin's share next to the share of everything else combined, as two numbers on one screen. No oscillator, no trend line, no season index — just the split, updated live, next to how far each coin sits from its own peak. The two numbers together answer most questions the market page of any news site is dancing around.