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.
Why dominance isn't the same as price
It's easy to assume rising dominance means Bitcoin's price is going up, but that's not necessarily true — dominance is a relative measure, not an absolute one. Bitcoin's dominance can rise even while its price falls, as long as altcoins are falling faster. Equally, dominance can fall even while Bitcoin's price rises, if altcoins happen to be rising even more sharply at the same time. Reading dominance correctly means remembering it always describes a relationship between Bitcoin and everything else, never Bitcoin in isolation.
ETH dominance and the rest of the picture
Bitcoin dominance gets most of the attention, but Ethereum's share of total market cap is worth tracking alongside it, since the two together typically account for a large portion of the entire tracked market. When both BTC and ETH dominance are falling together, that's a stronger signal of broad altcoin strength than either one falling on its own — it suggests capital is spreading out across many smaller assets rather than concentrating in just the second-largest coin. CryptoHeat's Market page surfaces both figures side by side for exactly this comparison.
A number to track over weeks, not minutes
Because dominance is a ratio built from two constantly moving numbers, it can look noisy if you check it too frequently. It's far more informative as a trend watched over days and weeks than as a single live reading. A single afternoon's dip in dominance is closer to normal market noise; a sustained multi-week decline is what actually characterizes the altcoin-season pattern people are usually referring to.