Bitcoin dominance is one of the most-watched macro metrics in crypto, and it's simpler than it sounds once you break down what it's actually measuring.
What dominance measures
Bitcoin dominance is Bitcoin's market capitalization expressed as a percentage of the total market capitalization of all tracked cryptocurrencies combined. If Bitcoin's dominance is 55%, that means Bitcoin represents 55% of the total value of every coin being tracked, with the remaining 45% spread across everything else.
Rising vs. falling dominance
Rising dominance generally means capital is concentrating in Bitcoin relative to altcoins — Bitcoin is either rising faster than the rest of the market, or holding up better during a decline. Falling dominance means altcoins are gaining ground relative to Bitcoin, either outperforming it in a rally or losing less in a downturn.
What "altcoin season" refers to
When dominance falls significantly over a sustained period, with a broad range of altcoins outperforming Bitcoin at the same time, that period is commonly referred to as an altcoin season. It's a description of a market pattern after the fact, not a prediction — dominance can reverse direction quickly, and it's most useful as one input alongside market breadth and volume, not a signal on its own.
Where to watch it
CryptoHeat's Market Pulse section shows live BTC dominance calculated from tracked market cap data, alongside overall market breadth — the two together give a fuller picture than either number alone.