Altcoin Season represents a distinct phase within the cryptocurrency market when alternative coins (collectively known as altcoins) experience significant growth and often surpass Bitcoin in investment returns. This shift in market momentum indicates a growing investor focus on various cryptocurrency projects beyond Bitcoin, leading many altcoins to achieve remarkable price surges.
An altcoin season is generally acknowledged to commence when approximately 75% or more of significant altcoins—typically from the top 50 or top 100 by market cap—have outperformed Bitcoin over a 90-day period. Analysts employ specialized metrics, known as Altcoin Season Indexes, to gauge this phenomenon by comparing the performance of altcoins directly to that of Bitcoin.
As an example, CoinMarketCap calculates its own Altcoin Season Index on a scale of 0 to 100: values exceeding 75 indicate the occurrence of an “altcoin season,” whereas readings below 25 point towards a “Bitcoin season.”
In past market cycles, periods of altcoin season have yielded exceptional returns for altcoins. For instance, during one altcoin season in 2021, major altcoins collectively achieved a staggering +174% return in just one quarter, while Bitcoin managed a mere +2% during the same timeframe.
Historically, altcoins start to gather momentum particularly when Bitcoin trades within about 10% of its all-time high. Currently, Bitcoin stands approximately 16% below its peak, with historical data showing that BTC has outperformed altcoins in around 54% of similar situations. However, if the price were to soar closer to $100,000, those odds could increase to roughly 58%.
Below, we will delve deeper into the implications of altcoin season and how it can enhance your understanding of cryptocurrency market dynamics.
Disclaimer: Cryptocurrency remains a high-risk asset class. This article serves purely for informational purposes and does not constitute investment advice. You could potentially lose your entire capital.
Key Takeaways
Altcoin season represents a shift in market dynamics where the majority of major altcoins outperform Bitcoin—typically indicated when over 75% of leading altcoins exceed BTC’s returns over a 90-day timeframe and Bitcoin dominance begins to decline.
Indicators of this season include a drop in both Bitcoin dominance and stablecoin market shares, increased trading volumes, and simultaneous growth across various crypto sectors, such as DeFi, NFTs, and meme tokens—demonstrating a rotation of capital towards higher-risk assets.
The altcoin season of 2025 was short-lived, concluding abruptly in mid-October as Bitcoin dominance surged back above 60%.
Understanding Altcoins
Altcoins encompass all cryptocurrencies apart from Bitcoin itself, ranging from prominent players like Ethereum, Solana, and XRP to smaller tokens and even stablecoins. A defined altcoin season is characterized by an environment where the majority of these alternative assets outperform Bitcoin in terms of market growth. This period is formally recognized when at least 75% of major altcoins have surpassed BTC’s returns over the previous three months, as previously mentioned.
In practical terms, an altcoin season often feels euphoric: altcoin prices soar to new heights, portfolios reflect double- and triple-digit returns, and the news is flooded with headlines celebrating new all-time highs across numerous assets.
This exhilarating phase typically lasts between two to six months, following which the market often undergoes a corrective phase. For this reason, seasoned traders frequently use altcoin season as an opportunity to lock in profits rather than engage in aggressive buying strategies. Historically, within mere months following these peaks, altcoins have seen their values plummet by 70–90%, erasing much of their earlier gains.
Signals for Beginning, Developing, and Concluding an Altcoin Season
Declining Bitcoin Dominance
Monitoring Bitcoin Dominance—Bitcoin’s share within the total cryptocurrency market capitalization—is crucial. A consistent decline in this metric indicates that the overall market is expanding at a rate faster than Bitcoin, capturing more capital. However, it is essential to assess the reasons behind the decline in dominance: stablecoins (such as USDT) also contribute to this metric. Therefore, a shift of capital into stablecoins can reduce Bitcoin’s dominance without representing real inflows into altcoins.
The true essence of an altcoin season typically emerges when both Bitcoin’s and stablecoins’ market shares are declining, suggesting capital is indeed shifting toward riskier altcoin investments.
Altcoin Season Index > 75
Specialized indexes that monitor the relative performance of altcoins in comparison to Bitcoin are valuable tools. When the index rises above 75, it officially confirms that most major altcoins have exceeded BTC’s gains over the analyzed period. Traders often watch this indicator alongside other market factors for further context.
A sharp upturn in this index, particularly following a prolonged period of low readings, indicates a market phase wherein most coins are outperforming Bitcoin. Conversely, a drop below 25 suggests that the leading altcoins are either underperforming Bitcoin or actually declining, signaling a “Bitcoin season.”
Rising Altcoin Volume and Market Cap
An observable increase in trading volume and market capitalization specifically among altcoins serves as a strong indicator. Analysts monitor segment growth—greater attention and investment into altcoins outside the top 10 often signals a rising risk appetite among investors and curiosity towards less popular projects.
During an altcoin season, trading volumes on exchanges commonly experience a notable uptick, reflective of both fresh capital entering the market and speculative traders engaging with altcoins.
Broad-Based Growth Across Multiple Sectors
In a classic altcoin season, growth is not confined to a single niche but rather witnessed across the entire market. Historical cycles reveal that numerous major sectors, such as DeFi protocols, Layer-1 platforms, Layer-2 solutions, NFT ecosystems, and even meme tokens, often rally together during these periods.
Behavioral and Media Indicators
An altcoin season is typically accompanied by heightened retail interest and a notable shift in overall market sentiment. Altcoins experience substantial mentions across social media, search trends spike, and online discussions are saturated with “the next big thing” narratives, along with memes celebrating instant wealth.
Investors may succumb to FOMO (fear of missing out), flocking towards rapidly appreciating altcoins. During peak excitement, even fundamentally weak tokens may see unexplained price surges—an indication of market euphoria that can lead to overheating.
What Transpired in September and October 2025?
However, by mid-October, the index plummeted to approximately 51 points (indicated by the orange marker), highlighting the sudden decline in market sentiment.
This shift indicates that the altcoin season of 2025 was relatively brief, effectively concluding after a market downturn in mid-October. Concurrently, Bitcoin dominance surged decisively from around 57% back to approximately 62%, amplifying the prevailing sentiment that marked the conclusion of the altcoin rally.
This increase in Bitcoin dominance is usually interpreted as a signal that the altcoin season has come to an end, with investors typically reallocating resources from higher-risk assets to more stable ones—primarily Bitcoin or stablecoins.
In the aftermath of October’s turbulence, some analysts predict that the altcoin market might regain its momentum by late 2025. However, the volatile nature of cryptocurrency markets makes future predictions uncertain; only time will reveal if another altseason will unfold before the end of the year.
The Bottom Line
Altcoin season presents both exceptional opportunities and considerable risks. In 2025, early indicators pointed to a burgeoning altseason underpinned by declining Bitcoin dominance and simultaneously surging altcoin values. Nevertheless, the market lesson was clear—instant wealth is rarely guaranteed, as shown by the subsequent altcoin crash in October.
To navigate an altcoin season successfully, investors must exercise discipline and strategy: recognize early warning signs, construct diversified portfolios diligently, resist the allure of market euphoria, and secure profits before the music ceases. A fleeting altseason can dramatically enhance your capital—provided you sidestep the pitfalls that ensnare unprepared traders.
