What Is Bitcoin Dominance?
Bitcoin Dominance (BTC.D) measures Bitcoin's market capitalization as a percentage of the total cryptocurrency market cap. When BTC dominance is rising, capital is flowing into Bitcoin relative to altcoins (risk-off). When it's falling, capital is rotating from Bitcoin into altcoins (risk-on, often called "altseason").
How Bitcoin Dominance Works
BTC dominance has ranged from ~30% (during altcoin euphoria in 2018 and 2021) to ~70% (during Bitcoin-only rallies). The metric cycles with the broader market: early in a bull cycle, Bitcoin leads and dominance rises; mid-cycle, capital rotates to large-cap alts; late-cycle, small-cap altcoins pump and dominance hits its low.
Why It Matters for Traders
BTC dominance is one of the most useful macro indicators for portfolio allocation. Rising dominance = overweight BTC, underweight alts. Falling dominance = increase alt exposure. The transition points (when dominance peaks and starts declining) are the most profitable moments to rotate from BTC to altcoins, as the subsequent alt outperformance can be dramatic.