What Is the Altcoin Season Index?

In June 2025, the cryptocurrency market witnessed a historic shift in a key indicator: the Altcoin Season Index plummeted to 16 on June 23, marking the lowest level since 2023. This value is not only far below the threshold of 75 for ‘altcoin season,’ but even below the dividing line of 25 for ‘Bitcoin season,’ indicating that the market is in a deep Bitcoin dominance period — with less than 13% of alts outperforming Bitcoin in the past 90 days. Such a low index was last seen in October 2024.

What is the altcoin season index?

This index is a core thermometer for measuring market capital rotation, with a clear quantitative operational logic:

• Data source: Tracks the 90-day performance of the top 50 or top 100 alts (excluding stablecoins and wrapped tokens) relative to Bitcoin (BTC);
• Judgment thresholds:
  • ≥ 75: Indicates the start of “altcoin season” (over 75% of alts outperform BTC)
  • ≤ 25: Enters “Bitcoin season” (BTC dominates the market)
  • 25-75: Neutral zone, indicating that capital rotation may be approaching;
• Market significance: An index below 25 indicates that funds are flowing into Bitcoin, reflecting investors’ pursuit of liquidity and security amid uncertainty.

Why Did the Altcoin Season Index Fall to Freezing Point?

The crash of this index in June was not an isolated event, but rather the result of multiple pressures:

1. Bitcoin’s Strong Suppression: Bitcoin reached a historical high of $111,900 in June, with a monthly increase of 26%, significantly lifting the benchmark. Its market dominance (BTC.D) remained above 50%, absorbing a large amount of market liquidity.
2. General Weakness in Alts: Most mainstream altcoins had a negative return rate over the past 90 days, with tokens like ENA, ETHFI, and STRK experiencing declines of over 40%. Meanwhile, the total market capitalization of altcoins shrank by 38% from its historical peak, evaporating approximately $600 billion.
3. Macro and Regulatory Suppression of Risk Appetite: The tightening of U.S. monetary policy has withdrawn market liquidity, combined with uncertainties such as SEC regulatory restructuring, further suppressing the willingness to transfer funds to high-risk altcoins.

Historical Patterns: Will the Altcoin Season Arrive After the June Low?

It is worth noting that extremely low index values often appear in June and have repeatedly served as a precursor to market turning points. According to analyst Michael van de Poppe’s statistics:

• Cyclical Lows: Since 2019, the index has reached low levels every June (2019/2020/2022/2023/2024 are all in June, while 2021 was in July);
• Rebound Patterns: After these lows, significant altcoin market movements often occur within 3-6 months. For example, after the index hit bottom in June 2020, a 20-month altcoin bull market began.

Analysts Atlas and OxNobler further pointed out that the current market structure is highly similar to that after the “COVID crash” in 2020 and before the altcoin season outbreak in 2021—deep drop, consolidation, and then breakthrough. OxNobler predicts that if the historical trajectory is followed, the total market cap of alts could experience a tenfold explosive growth.

What metrics support the approaching copycat season?

Despite the downturn in the index, on-chain and technical indicators are accumulating positive momentum:

• Ethereum Ecological Recovery:
  • The throughput of Layer 2 networks (such as Base) exceeded 500 TPS, an annual increase of 36%, laying the foundation for DeFi and GameFi projects.
  • The ETH/BTC exchange rate ended a 669-day downtrend with weekly support formed, similar to the structure before the start of early 2020.
• Sufficient “fuel” for stablecoins: The total market capitalization of global stablecoins reached $260 billion, and compliant stablecoins grew by 104% year-on-year. Huge amounts of money are waiting on the sidelines and can quickly translate into altcoin buying power once the mood turns.
• The capital rotation has been tentative: some small-cap tokens have skyrocketed, indicating that high-risk funds have begun to enter the market partially.

Key Contradiction: Will Bitcoin’s Continued Strength Block Rotation?

Bitcoin’s performance remains the biggest variable. If its price maintains high volatility and its dominance does not fall below 50%, funds may find it difficult to flow into alts on a large scale. We need to be wary of the “double top” risk - BTC’s weekly RSI shows bearish divergence, and trading volume is shrinking, similar to the signals seen before the peak in 2021.

Investor Strategies: How to Position for Potential Turning Points?

Currently in the Bitcoin season, it is the window period for selecting targets and laying out positions at low levels:

1. Monitor index breakout signals: If the index rises above 50 and stabilizes, it can be considered that the probability of alts season has greatly increased;
2. Focus on leading sectors:
   • AI track tokens (such as RNDR, VIRTUAL)
   • Ethereum L2 ecosystem tokens (such as ARB, STRK) have recently shown high sensitivity to capital rotation;
3. Adopt a dollar-cost averaging strategy: Gradually accumulate quality alts during periods of index stagnation to lower the average cost.

Conclusion

Historical data shows that a period of deep Bitcoin dominance is often the prelude to an altcoin explosion. Although the current Altcoin Season Index is at an extreme low of 16, the adoption of Ethereum L2, the buildup of stablecoins, and the bottoming of the ETH/BTC exchange rate are all accumulating energy for a reversal.

The market is on the eve of a silent rotation—when the index climbs out of the deep valley and breaks through the 50 midline, it may be the moment the alts season horn is sounded. For investors, patient research and selective positioning at this moment may become the key to capturing the next wave of trends.