Altcoin season is a stretch of weeks or months in which most cryptocurrencies other than Bitcoin rise faster than Bitcoin does. The word altcoin simply means any coin that is an alternative to Bitcoin, from Ether and Solana down to the smallest tokens. During an altcoin season, money that had been concentrated in Bitcoin spreads out across the rest of the market, and smaller coins post much larger percentage gains.
There is no official start or end. Altcoin season is a label traders apply after looking at a few measures, and this guide explains those measures and what history shows.
How the Altcoin Season Index works
The best known yardstick is the Altcoin Season Index published by Blockchain Center. It looks at the 50 largest coins, leaves out stablecoins and asset-backed tokens, and asks one question: how many of them beat Bitcoin over the past 90 days?
- 75% or more beat Bitcoin: the index calls it altcoin season.
- 25% or fewer beat Bitcoin: it is Bitcoin season.
- Anything in between: neither side is clearly leading.
CoinMarketCap publishes a similar index based on the top 100 coins, and other data sites have their own versions. Because the coin lists and time windows differ, the readings do not always match. The idea is the same in all of them: altcoin season is about breadth, meaning how many coins are outperforming, not about one or two tokens having a good week.
Other signals traders watch
- Bitcoin dominance. This is Bitcoin’s share of the total crypto market value. A steady fall over several weeks means other coins are growing faster.
- The ETH/BTC pair. When Ether gains on Bitcoin, it has often been an early sign that money is moving toward riskier assets.
- Trading volume in smaller coins. A rise in the share of exchange volume going to altcoins shows where activity is shifting.
- Stablecoin supply. Growth in stablecoins can indicate new money waiting on the sidelines, though it does not say where that money will go.
The usual sequence
Past cycles have followed a loose order. Bitcoin rises first and draws attention. Once it slows or moves sideways, large coins such as Ether catch up. Gains then spread to mid-sized coins, and finally to small and speculative tokens. That last stage has tended to arrive late in a bull market and to end abruptly. The order is a pattern from a small number of cycles, not a rule.
When it has happened before
- Late 2017 to January 2018. The initial coin offering boom pushed thousands of new tokens higher, and Bitcoin’s share of the market fell below 40% for the first time. Most of those tokens lost more than 90% in the year that followed.
- Early 2021. Between January and May 2021, decentralised finance tokens, NFT-related coins and meme coins such as Dogecoin surged while Bitcoin dominance dropped from about 70% to about 40%. The move ended with a market-wide sell-off in May.
Since then, rallies in smaller coins have been shorter and narrower. One reason is supply: there are now many times more tokens competing for the same money. Another is that spot Bitcoin exchange-traded funds, launched in the United States in January 2024, channel institutional money into Bitcoin without it ever reaching other coins.
Why altcoins move more than Bitcoin
Smaller coins have lower market value and thinner order books, so the same amount of buying moves the price further. The reverse is also true. In a downturn, altcoins usually fall faster and further than Bitcoin, and many never recover their earlier highs. A coin that drops 90% has to rise tenfold to get back to where it started.
Risks to keep in mind
- Altcoin seasons are identified with confidence only in hindsight.
- Liquidity can vanish quickly in small tokens, which makes it hard to sell at the quoted price.
- Token unlocks can add new supply at the same time as demand fades.
- Promotions on social media tend to peak near the end of a rally, not the start.
Frequently asked questions
When is altcoin season?
There is no calendar for it. By the most common definition it is in effect when at least 75% of the top 50 coins have outperformed Bitcoin over the previous 90 days.
How long does altcoin season last?
The two clearest examples lasted roughly two to five months. Shorter bursts of a few weeks are more common.
Does Bitcoin have to fall for altcoin season to start?
No. In past cycles it usually began while Bitcoin was stable or still rising slowly. A sharp fall in Bitcoin normally pulls the whole market down.
Where can I follow the coins that are moving?
We cover daily moves in Altcoin News and Trending Cryptos, with Bitcoin itself in Bitcoin News.
This guide is educational and is not investment advice. Crypto assets are volatile and you can lose money.
