Altseason (short for “altcoin season”) is a period in the crypto market cycle when altcoins significantly outperform Bitcoin, often delivering multiples of Bitcoin’s returns in a short time. Altseason typically occurs after Bitcoin has made a strong bull run and begun to consolidate or slow its gains — at which point profits rotate out of BTC into smaller-cap altcoins in search of higher percentage returns. During peak altseason, it’s not uncommon for mid and small-cap altcoins to gain 200–1,000%+ in weeks while Bitcoin moves 10–20%.
How to identify and trade altseason: Bitcoin Dominance (BTC.D) — Bitcoin’s share of total crypto market cap. When BTC.D falls significantly (e.g. from 60% to 45%), capital is flowing into altcoins — a classic altseason signal; Altcoin Season Index (from Blockchain Center) — measures how many of the top 50 altcoins have outperformed BTC over 90 days; above 75 signals altseason; ETH/BTC ratio — Ethereum typically leads altseason; a rising ETH/BTC ratio signals the alt cycle is beginning; and Narrative rotation — specific sectors (AI, DeFi, Layer 2, meme coins) take turns leading. Altseason is the most exciting — and most dangerous — phase of the crypto cycle. Many traders over-allocate to low-quality alts, only to be caught when the cycle turns. Strong risk management and profit-taking discipline are essential.
Example: BTC consolidates at $60,000 for 6 weeks. Bitcoin Dominance drops from 58% to 48%. ETH rallies 60%. Small-cap AI tokens surge 300–1,000%. A prepared trader has an altcoin watchlist ready and trades the rotation with defined profit-taking levels.
Learn more: Blockchain Center — Altcoin Season Index
