At the top of our homepage, next to total market cap and 24-hour volume, sits a percentage labelled "BTC Dominance." It is one of the oldest signals in crypto, and one of the most misread. This guide explains what it measures and how traders actually use it.

The simple definition

BTC dominance is Bitcoin's market capitalisation divided by the market capitalisation of every cryptocurrency combined. If all crypto together is worth two trillion dollars and Bitcoin alone is worth one trillion, dominance is 50 percent. Nothing more mysterious than that.

Why the number changes

Dominance is a ratio, so it moves for two different reasons, and telling them apart matters:

  • Bitcoin outperforming. If Bitcoin's price rises faster than the rest of the market, or falls more slowly, dominance climbs even if every coin is losing value.
  • Altcoins outperforming. When money rotates into smaller coins and they rally harder than Bitcoin, dominance falls even while Bitcoin's own price is rising.

This is why dominance can rise during a crash: in fearful markets, money tends to retreat from speculative small coins into Bitcoin, the way stock investors retreat into blue chips.

How traders read it

A rising dominance is often read as a "risk-off" signal inside crypto — capital consolidating into the largest, most liquid asset. A falling dominance during a broad rally is the classic sign of what traders call altcoin season, when smaller coins outperform. Some traders watch for dominance to break long-term levels on the chart before rotating their portfolios between Bitcoin and altcoins.

The limitations nobody should ignore

Dominance is a blunt instrument. Stablecoins — tokens pegged to the dollar — now make up a meaningful slice of total crypto market cap, and they sit in the denominator of the calculation. When people sell volatile coins for stablecoins, dominance falls slightly even though nothing bullish happened to altcoins. Market cap itself can also be distorted by coins with large supplies that rarely trade. Treat dominance as one piece of context, never as a trading signal on its own.

Using it on our tracker

Our dominance figure updates automatically through the day. A practical habit: glance at it alongside total market cap. Rising market cap with falling dominance suggests a broad rally led by altcoins; falling market cap with rising dominance suggests a defensive market hiding in Bitcoin. Two numbers, read together, tell you more than either does alone.