"Altseason is coming!"
You hear this sentence every crypto cycle. On Twitter. On YouTube. In Discord groups. Some influencer shows a chart of Bitcoin dominance and says: "When dominance drops, altcoins pump. Altseason confirmed!"
And then? Thousands of people buy altcoins. Some go up. Most don't. And in the end everyone's sitting on red portfolios wondering: "Where was the altseason?"
I looked at the data. Not the opinions. The data.
In this article you'll learn:
- What "altseason" means and how it's measured
- Whether it historically actually exists (spoiler: partially)
- Why most people still lose money
- And what that means for your strategy
What Is Altcoin Season?
The definition is simple: when 75% of the top 100 altcoins outperform Bitcoin over 90 days, it's "altseason." The Altcoin Season Index from Blockchain Center measures exactly that.
Related to this is the concept of Bitcoin dominance: Bitcoin's share of the total crypto market capitalization. When Bitcoin is dominant (high share), little money flows into altcoins. When dominance drops, money flows from Bitcoin into altcoins.
The theory: Bitcoin pumps first. Then investors take their Bitcoin profits and put them into altcoins. Altcoins pump harder (because smaller, less liquid). That's the "rotation."
Sounds logical. But is it true?
The Historical Data
2017: The Great Altseason
This was the real, undisputed altseason.
- Bitcoin dominance dropped from 87% to under 38% (low point: 31% in January 2018)
- Ethereum went from $8 to $1,400 (+17,400%)
- Coins like NEO, VeChain, and Cardano did 50-100x
- Practically EVERYTHING went up. Even complete garbage.
Thesis: Why it worked: It was the first time the mainstream discovered crypto. New money was flooding into the market. And there were only a few thousand coins. Today there are over 2 million.
2021: The Half Altseason
Bitcoin dominance dropped from 70.7% (January 2021) to under 40%. The Altcoin Season Index reached 98 on April 16, 2021. The total crypto market rose +200%, while Bitcoin "only" did +63%.
- Ethereum: +800%
- Solana: +20,000%
- DOGE: Elon Musk tweeted, and suddenly a dog coin was worth billions
- DeFi and NFTs exploded
Thesis: Why it ONLY HALF worked: Not ALL altcoins went up. Many ICO coins from 2017 were dead. The rotation was more selective. Those who had the RIGHT altcoins got rich. Those who had the wrong ones lost everything.
2024-2025: The Disappointed Altseason
Everyone expected it. Bitcoin reached new all-time highs. And indeed: at the end of 2024 BTC dominance briefly dropped to 55% and altcoin market capitalization rose above $1,500 billion. It LOOKED like the beginning of an altseason.
But it wasn't.
Early 2025 the trend reversed: BTC dominance climbed back above 60%. Altcoin market capitalization crashed from $1,500B to under $900B. Within a few months altcoins lost 40% of their value, while Bitcoin held steady.
- The Altcoin Season Index briefly rose to 78 in September 2024, then fell to 20
- Individual altcoins had short pumps (Solana, XRP, some memecoins)
- But a BROAD altseason where 75% of all altcoins pump? Never came
Thesis: Why it DID NOT work: Bitcoin had spot ETFs. Institutional money flowed directly into Bitcoin, not into the broader crypto market. The "rotation" briefly happened (Q4 2024), but money quickly flowed back into BTC. Without sustained inflows into altcoins, the pump was a flash in the pan.
The following chart shows the relationship over 10 years. Orange = BTC dominance. Purple = altcoin market capitalization. You can see: 2017 and 2021, dominance went down and altcoin mcap went up (real altseasons). 2025 saw a brief altcoin peak, but dominance immediately rose again. Hover for exact values:
The Uncomfortable Truth
Here are the facts no influencer tells you:
1. Altseason is ALWAYS only recognized in hindsight.
While it's happening, nobody knows if it's "the real one" or just a short pump. In September 2024 everyone screamed "Altseason!" The index was at 78. Three months later: 20. Was it altseason? No. But thousands had already bought altcoins.
2. Even in real altseasons, MOST people lose money.
2021: Solana did +20,000%. But who bought at the bottom? Almost nobody. Most bought AFTER Solana had already risen 500%. And sold at -60%.
The winners of an altseason are those who bought BEFORE the altseason. If you read "altseason confirmed!" and THEN buy, you're too late.
3. 99% of altcoins are worthless.
There are over 2 million cryptocurrencies. In the 2021 altseason maybe 500 rose significantly. That's 0.025%. The other 99.975% either died or underperformed Bitcoin.
"Investing in the altseason" means: you have to find the right 500 out of 2 million coins. BEFORE the pump. Good luck.
Remember: Altseason exists as a phenomenon. But using it as an investment strategy is like playing the lottery and calling it "financial planning."
Bitcoin Dominance as a Signal?
Many use Bitcoin dominance as a timer: "When dominance drops, I buy altcoins."
The problem:
Dominance can drop for different reasons:
- Money flows from Bitcoin into altcoins (bullish for alts) ✅
- Bitcoin crashes FASTER than altcoins (bearish for everything) ❌
- New stablecoins are issued and dilute dominance (irrelevant) ❌
You don't know WHY dominance is dropping. And the reason determines whether altcoins go up or not.
2022: Bitcoin dominance dropped from 48% to 40%. Was that altseason? No. Everything crashed. Altcoins just faster than Bitcoin. Luna went to zero. Celsius went bankrupt. The falling dominance was a death signal, not a buy signal.
What I Learned from This
I don't trade altseason. My main bot trades only BTC spot. Why?
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Bitcoin is predictable. It has the longest track record, the most liquidity, the best data. I can backtest strategies.
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Altcoins are unpredictable. Which one goes up? When? Why? Too many unknowns for a systematic system.
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The risk-reward ratio doesn't add up. Yes, Solana did +20,000%. But for every Solana winner there were 1,000 coins that went to zero. The expected value is negative.
The one exception: one of my bots (The Genius) trades DeFi tokens. But not based on "altseason" or dominance charts. Based on concrete events at established protocols. That's fundamentally different from "buying the altseason."
What You Can Do Instead
If you still want to invest in altcoins:
1. Maximum 10-20% of your crypto portfolio. The rest stays in BTC.
2. Only projects with real utility. Ethereum, Solana, Aave. No random tokens from Twitter.
3. Buy BEFORE everyone is screaming "altseason." When the index is at 20, not at 78.
4. Have an exit strategy. Not "I'll sell when I have enough profit." But: "I sell 50% at 3x and the rest at 5x."
5. Or simply: Buy BTC, hold, sleep. In my backtest that beat 27 out of 30 active strategies.
Remember: Altseason is like a thunderstorm. You know it comes sometimes. But you don't know when, where, or how strong. And anyone who goes outside with an umbrella when the sun is shining looks stupid. Until it rains.
→ HODL Beats 27 Out of 30 Strategies — Why BTC beats almost everything
→ FOMO: Why You Always Buy Too Late — Altseason and FOMO are siblings
→ Musical Chairs: Memecoins — Who pays for your altcoin profit?
→ DCA Savings Plan Calculator — What a boring Bitcoin savings plan would have returned
→ What's the Bot Saying Right Now? — Current signal
Your Dominic, the guy who waited for the 2024 altseason. It never came.
Sources
- Blockchain Center: Altcoin Season Index
- CoinMarketCap: Altcoin Season Index
- TradingView: Bitcoin Dominance Chart
- Tangem: What is Altseason? (2026)
Disclaimer: This is not financial advice. Altcoins are highly volatile and many lose their entire value. Only invest what you can afford to lose.
