Bitcoin Dominance at 58% Amidst Rising Altcoin Season

Bitcoin's share of the total crypto market value is known as Bitcoin dominance, or BTC.D. It stands at around 58.3% as of late September 2026.

This figure reflects not just Bitcoin's own price but its price relative to everything else in the market. Several forces push Bitcoin dominance up and down, including institutional ETF inflows into Bitcoin, risk-off sentiment that sends capital into Bitcoin, individual altcoin rallies, and new capital entering crypto for the first time.

The Altcoin Season Index is a useful metric to pair with Bitcoin dominance. It tracks what percentage of the top 100 altcoins have outperformed Bitcoin over the trailing 90 days. A reading above 75 signals a genuine altcoin season, while below 25 indicates Bitcoin season. The index has been climbing toward the 60s as of late September.

It's essential to read both metrics together properly. Falling Bitcoin dominance and a rising Altcoin Season Index indicate broad rotation into altcoins, signaling an altseason. Rising dominance with a falling index suggests capital is fleeing to Bitcoin, indicating risk-off sentiment.