What Is Altcoin Season? Meaning, Definition & Index
What is altcoin season? A plain-English definition of alt season, how the altcoin season index is measured, and the signals that tend to come before it.
· 8 min read
If you have spent any time in crypto forums, you have seen someone ask "is it alt season yet?" So what is altcoin season, exactly? In short, it is a stretch of the market when most altcoins (every coin that is not Bitcoin) rise faster than Bitcoin itself. The phrase is used loosely on social media, but there is also a measurable version: the altcoin season index, which checks how many of the largest coins have beaten Bitcoin over the last 90 days.
This guide explains the alt season meaning in plain terms, how the index is calculated, why these periods happen, and how DanioX reads them as part of a wider market-season framework.
Key takeaways
- Altcoin season is a period when the majority of large altcoins outperform Bitcoin, not simply a period when prices go up.
- The most common definition: at least 75% of the top 50 coins (excluding stablecoins and asset-backed tokens) have outperformed BTC over the last 90 days.
- The opposite state is "Bitcoin season": 25% or fewer of those coins have beaten BTC.
- Alt seasons have historically come late in bull markets, after Bitcoin has already made a strong move.
- The index is a lagging, backward-looking measure. Leading clues come from Bitcoin dominance, the ETH/BTC ratio and wider liquidity.
What is altcoin season? The plain-English definition
The simplest altcoin season definition is this: a phase where holding a broad basket of altcoins would have done better than holding Bitcoin.
Two points in that sentence matter.
First, it is relative. Alt season is about altcoins versus Bitcoin, not altcoins versus the US dollar. In a strong bull market, Bitcoin and altcoins can both rise in dollar terms while Bitcoin still rises faster. That is not alt season. Equally, in theory, altcoins could fall less than Bitcoin in a downturn and technically "outperform" it, although in practice the index rarely reaches alt-season levels in bear markets.
Second, it is broad. One or two coins pumping does not make an alt season. A single sector rally (for example, a burst of interest in AI tokens or meme coins) can happen while most of the market still lags Bitcoin. Alt season means the outperformance is spread across most of the large caps.
Alt season meaning vs. "the market is up"
Many beginners treat "alt season" as a synonym for "bull market." They are different things:
| State | What it means | What typically leads |
|---|---|---|
| Bull market | Most crypto prices rising in USD | Liquidity, ETF/stablecoin inflows, risk appetite |
| Bitcoin season | BTC beating most altcoins | Capital concentrating in the largest, most liquid asset |
| Altcoin season | Most large altcoins beating BTC | Capital rotating out of BTC into ETH, then large caps, then smaller coins |
| Bear market | Most prices falling in USD | Tightening liquidity, risk-off |
You can be in a bull market and a Bitcoin season at the same time. In fact, that is common in the early and middle part of a cycle.
How the altcoin season index is measured
The most widely referenced version of the altcoin season index was popularised by Blockchaincenter. Its rules are straightforward:
- Take the top 50 coins by market cap.
- Exclude stablecoins (such as USDT and USDC) and asset-backed tokens (such as wrapped or gold-backed tokens), because they are not meant to move like independent assets.
- Measure each coin's price performance over the last 90 days.
- Count how many of them performed better than Bitcoin over the same 90 days.
- Express that as a score from 0 to 100.
The thresholds:
- 75 or above: Altcoin Season. At least 75% of those coins beat BTC.
- 25 or below: Bitcoin Season. Only a quarter or fewer beat BTC.
- Between 25 and 75: neither. The market is mixed.
Other data sites publish their own versions. CoinMarketCap, for example, runs an altcoin season index with its own coin list and settings, so readings can differ from one source to another. The idea is the same: count how many large coins are beating Bitcoin over a set window.
You can see a live reading and the history on our altcoin season index page.
Why 90 days?
A 90-day window is long enough to filter out a single week of noise, but short enough to react within one season of the market. The trade-off is that the index is slow. By the time 75% of coins have outperformed BTC across three months, a large part of the move has usually already happened. Treat the index as confirmation, not a timing tool.
Limitations worth knowing
- Survivorship and list changes. The top 50 changes over time. New coins enter, others drop out, and that affects the count.
- Equal weighting. Each coin counts once, whether it is worth hundreds of billions or a few billion. A move in a mid-sized coin counts as much as a move in Ethereum.
- Threshold effects. A reading of 74 and a reading of 76 describe almost the same market, but one says "alt season" and the other does not.
- It says nothing about USD returns. A score of 80 tells you altcoins beat Bitcoin, not that anyone made money.
Why does alt season happen?
Crypto capital tends to move in a rough order, from the biggest and most liquid assets down to the smallest and riskiest. A simplified version of that rotation:
- New money arrives through Bitcoin first, because it is the easiest asset to buy in size, and it has spot ETFs and deep liquidity.
- Bitcoin rises and becomes the story. Its share of the total market (Bitcoin dominance) usually climbs.
- Bitcoin slows or consolidates. Traders who made gains on BTC look for assets that have not moved as much.
- Ethereum starts to outperform. The ETH/BTC ratio turns up.
- Large-cap altcoins follow, then mid caps, then small caps and meme coins, often with rising leverage and speculation.
Not every cycle follows this script cleanly, and the gaps between steps vary. But this pattern explains why alt seasons have historically appeared late in bull runs, as they did in the broad altcoin rallies of 2017–18 and 2021. It also explains why they tend to end sharply: the last phase is driven by the riskiest coins and the most leverage.
What comes before alt season: the leading signals
Because the index only confirms what already happened, DanioX watches a small set of leading gauges. We cover these in more depth in when is altcoin season, but here is the short version.
Bitcoin dominance falling while BTC holds
Bitcoin dominance (BTC.D) is Bitcoin's share of the total crypto market cap. When BTC.D rises, Bitcoin is outperforming and altcoins bleed against it. When BTC.D falls while Bitcoin's price holds up or rises, money is moving into altcoins rather than leaving crypto altogether. That second combination is the classic alt-season backdrop.
The "while BTC holds" part is important. If BTC.D falls because Bitcoin is crashing and everything else is crashing slightly less, that is not an alt season. It is a sell-off. See bitcoin dominance explained for how we separate the two.
ETH/BTC turning up
Ethereum is usually the first large altcoin to attract rotating capital. A rising ETH/BTC ratio has often been the trigger that pulls the rest of the altcoin market along. We treat a sustained ETH/BTC uptrend as the rotation signal.
Breadth
Breadth is the share of coins in their own uptrend. If only Bitcoin and a handful of large caps are in uptrends, the market is narrow. When many coins are trending up at the same time, conditions are broad enough for an alt season to develop.
Liquidity and the dollar
Altcoins are high-risk assets, and they need easy financial conditions. A weakening US dollar index, falling bond yields and calm volatility have historically been friendlier to risk. Our dollar index crypto page tracks the DXY side of this.
How DanioX labels the market season
Rather than a single number, our signals page combines several readings into a market season label:
| Reading | Leans Bitcoin season | Leans altcoin season |
|---|---|---|
| Altcoin season index | 25 or below | 75 or above |
| Bitcoin dominance | Rising | Falling while BTC holds |
| ETH/BTC | Falling | Rising |
| Breadth | Narrow | Broad |
| Dollar / liquidity | Strong dollar, rising yields | Weak dollar, easing yields |
When most rows point the same way, the label is clear. When they conflict, we call the market "mixed" and suggest caution. The full rules are on the methodology page.
Common mistakes around alt season
- Calling it too early. One green week in altcoins is not a season. Wait for dominance, ETH/BTC and breadth to agree.
- Buying the smallest coins first. Rotation usually runs from large to small. Small caps tend to move last and fall hardest.
- Ignoring the exit. Alt seasons have historically been short compared with the rest of the cycle. Plan targets and stops before you enter.
- Confusing narrative with breadth. A hot sector can outperform while the broad market does not.
FAQ
What is altcoin season in crypto?
It is a period when most large altcoins outperform Bitcoin. On the most common index, that means at least 75% of the top 50 coins (excluding stablecoins and asset-backed tokens) beat BTC over the previous 90 days.
What is alt season, and is it the same as altcoin season?
Yes. "Alt season," "altseason," "alt coin season" and "altcoin season" all refer to the same thing: altcoins broadly beating Bitcoin.
What does an altcoin season index of 75 mean?
It means 75% of the coins in the index outperformed Bitcoin over the last 90 days. That is the usual threshold for calling it alt season. A reading of 25 or below indicates Bitcoin season.
Is altcoin season the same as a bull market?
No. A bull market means prices are rising in dollar terms. Altcoin season is about relative performance against Bitcoin. Bitcoin can lead a bull market for months while altcoins lag.
How long does altcoin season last?
There is no fixed length. Historically, broad alt rallies have been shorter than the Bitcoin-led phases before them and have often ended abruptly. Watch the live altcoin season index and dominance rather than relying on a set duration.
What is the opposite of altcoin season?
Bitcoin season, when 25% or fewer of the top coins beat Bitcoin over 90 days. It usually coincides with rising Bitcoin dominance.
Educational content, not financial advice.