Altcoin Season Index + Bitcoin Dominance
[!] Not financial advice. Outputs are estimates based on public market data. Crypto is volatile. Full disclaimer.
Updated every hour · CoinGecko top-50 data
--
Altcoin Season Index (0-100)
--
BTC Dominance
--
Current State
What is "Altcoin Season"?
An Altcoin Season Index measures how many of the top 50 altcoins outperformed Bitcoin over the past 90 days. The index ranges 0–100:
- 75–100 — Altcoin Season. Most alts beating BTC.
- 25–74 — Mixed market.
- 0–24 — Bitcoin Season. BTC outperforming most alts.
Bitcoin Dominance
BTC Dominance is Bitcoin's market cap as a percentage of total crypto market cap. Rising dominance often correlates with risk-off sentiment; falling dominance with altcoin rallies.
How we calculate
We re-implement the standard CoinMarketCap Altcoin Season Index methodology directly from CoinGecko's top-50 data, with hourly updates (CMC publishes daily). See Methodology for the exact formula.
Related Tools
About · Disclaimer · Methodology · Editorial · Contact
Reviewed by Marcus Chen, CFA · Last updated: 2026-06-02
Data: CoinGecko Public API (hourly)