When Will Altcoin Season Start?

The question “when will altcoin season start” is central to current crypto market trends 2025. Altcoin season, or “altseason,” refers to the moment when altcoins outperform Bitcoin in both price and momentum. 

As September 2025 approaches, many traders wonder if this could be the next altcoin season, with conditions building for a possible shift from Bitcoin into alternative coins.

What Is Altcoin Season and How Does It Compare to Bitcoin Cycles?

Altcoin season describes a short-lived but powerful trend when investors move funds away from Bitcoin into other cryptocurrencies such as Ethereum, Solana, or smaller tokens. During these cycles, altcoins often show sharper gains than Bitcoin because of their higher volatility and smaller market capitalisations.

Historically, Bitcoin dominates first. After a strong bull run, Bitcoin often consolidates, moving sideways. At this stage, risk-seeking investors start looking at alternatives. 

Ethereum typically benefits first, and then capital spreads into mid-cap and small-cap coins. This flow of liquidity lowers Bitcoin’s market dominance and creates conditions for what analysts call “altseason.”

Looking back, the altcoin season of 2017–2018 was fuelled by the boom in initial coin offerings. Bitcoin’s market share fell from above 85% to below 40%, and new projects multiplied rapidly. In contrast, the 2020–2021 altseason was defined by meme coins and NFTs, with Bitcoin dominance again falling below 40% while altcoins surged.

When compared with Bitcoin-only rallies, altcoin seasons appear riskier but potentially more rewarding. Bitcoin tends to offer relative stability, while altcoins offer sharper, shorter opportunities. This comparison highlights the trade-off: stability versus explosive growth.

Read Also: Altcoin Season Indicator CMC: How to Read and Understand It?

Will Altcoin Season 2025 Begin in September?

Forecasting the exact start of altcoin season 2025 is challenging. However, September may bring several factors together that could ignite such a cycle.

One factor is monetary policy. If central banks, particularly the U.S. Federal Reserve, cut interest rates, global markets may shift into a risk-on environment. Altcoins usually perform better in these conditions because investors seek higher potential returns.

Another factor is regulatory clarity. Approval of exchange-traded funds for coins like Ethereum or Solana, or clearer rules for digital assets, could boost institutional confidence. Institutions often hesitate to back altcoins without clear frameworks, but regulation can provide a spark.

Market history also provides context. September has not always been favourable for Bitcoin, and weaker Bitcoin momentum often helps altcoins gain attention. If Bitcoin consolidates while trading volumes in Ethereum and other coins rise, the altcoin season index may climb closer to the 75/100 threshold that typically signals the start of altseason.

Still, uncertainty remains. The index currently sits around 41, meaning the market has not yet entered altcoin season. Until Bitcoin’s dominance falls significantly and altcoins consistently outperform, the next altseason cannot be confirmed.

Read Also: Altseason Signals? All Eyes on Jamie Coutts Bullish

Key Signals That Altcoin Season Has Started

Spotting the beginning of altcoin season early is vital for traders and investors. Several indicators provide clues:

Altcoin Season Index

This tool measures how many altcoins outperform Bitcoin over a set period. A score above 75 usually indicates altseason. However, by the time this happens, many early gains may already have been made.

Bitcoin Dominance Decline

A clear reduction in Bitcoin’s share of the total crypto market cap is one of the strongest signals. For example, in April 2021, Bitcoin dominance fell from 70% to 38%, aligning with explosive growth across altcoins.

Rising Trading Volumes

A surge in trading activity across a wide range of altcoins points to increased interest and liquidity. This usually occurs just before or during an altcoin season.

Retail Enthusiasm

Social media activity, sudden hype around smaller projects, and fear of missing out (FOMO) often mark the emotional side of altcoin seasons.

Yet caution is critical. Many altcoins rise quickly only to collapse just as fast. Some projects lack transparency, and in certain cases, even the official whitepapers are inaccessible. This makes them risky investments. While altcoin season can deliver short-term gains, it also exposes investors to sharp downturns.

Read Also: Altcoin Season Index Value Today: Is Altseason Coming Soon? 

Conclusion

Altcoin season 2025 may or may not begin in September, but the conditions are being closely watched. If Bitcoin consolidates, interest rates fall, and regulation improves, altcoins could take the spotlight once again.

However, altseason is not guaranteed. The Altcoin Season Index remains below key levels, and the crypto market is notoriously unpredictable. Investors should treat altcoin season as an opportunity, but also as a risk. Careful research and risk management are essential, particularly since some coins offer little transparency or fundamental support.

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FAQ

What is the altcoin season index?

It measures how many altcoins outperform Bitcoin over a period. A score above 75 suggests an active altseason.

When is altcoin season 2025 likely to start?

It may begin if Bitcoin consolidates, liquidity improves, and altcoin volumes rise. September could offer conditions, but nothing is certain.

How does Bitcoin compare to altcoins in altseason?

Bitcoin is more stable, while altcoins move faster but with higher risk. Altseason usually sees altcoins outperform.

How long does altcoin season last?

It generally lasts weeks to a few months, though timing varies across cycles.

Is investing in altcoin season safe?

No. It carries high risks. Altcoins can rise sharply but also collapse quickly, especially those with unclear fundamentals.