The altcoin market capitalization is nearing its all-time high, with many analysts predicting significant growth in September. This trend indicates a notable phase of acceleration in the altcoin season, suggesting that investments in altcoins are likely to yield profitable returns. Here are key observations supporting this view.
First, a shift in trading volume has been evident, with altcoin trading volume surpassing that of Bitcoin (BTC) and Ethereum (ETH) for the first time in September. Analyst Maartunn pointed out that this change is a strong indicator that capital is flowing away from BTC and ETH and into mid- and small-cap altcoins. Data from CryptoQuant corroborates this trend, showing altcoins accounted for 37.2% of total trading volume while ETH and BTC stood at 31.8% and 30.9%, respectively. This rotation of liquidity signals a potential new phase in the altcoin market, traditionally following a Bitcoin rally.
Moreover, there is evidence of a bearish sentiment surrounding Bitcoin, with 8 out of 10 indicators in CryptoQuant’s bull/bear score indicating a bearish trend. As Bitcoin dominance declines and altcoin market capitalization rises, the preference for altcoins becomes increasingly evident.
Secondly, the Altcoin Season Index (ASI) from Blockchain Center has reached an impressive 80 points, the highest level in 2025. The ASI measures how the top 50 cryptocurrencies (excluding stablecoins) have performed compared to Bitcoin over the past 90 days. A score of 80 indicates that 75% of these coins have outperformed Bitcoin, confirming an ongoing altcoin season. Historically, the ASI can escalate to 100 before it completes its cycle, reflecting a strong interest in high-risk altcoin investments.
Analyst Lau noted that the acceleration phase of the altcoin season can last anywhere from 17 to 117 days, emphasizing that the current cycle is still in the early stages.
Technical analysis also paints a bullish picture for altcoins. The total altcoin market capitalization (excluding BTC and ETH), known as TOTAL3, is forming a significant bullish triangle pattern. Charts suggest that TOTAL3 is testing its all-time monthly highs, with increasing volume and pricing approaching resistance levels. A breakout from this triangle pattern would signal a robust acceleration of the altcoin season, reminiscent of trends witnessed during past cycles between 2019 and 2021.
Simon Dedic, founder of MoonrockCapital, highlighted the importance of this structural signal, noting that the impending breakout could lead to unparalleled investor confidence in altcoins. If TOTAL3 manages to surpass the $1.16 trillion threshold, it would set new historical highs, creating a momentum driven potentially by retail investors’ fear of missing out.
Lastly, a surge in new altcoin listings on major exchanges like Upbit, Coinbase, and Bithumb is further driving interest in altcoins. Upbit has been particularly active, listing nearly one new token daily, thereby maintaining its 50.6% market share against Bithumb’s 46%. Similarly, Bithumb and Coinbase have expanded their listings, enhancing liquidity and speculation in altcoins. These new entries are expected to invigorate trading volumes, creating a feedback loop that reinforces the current altcoin season.
In summary, the combination of shifting trading volumes, a high Altcoin Season Index, bullish technical patterns, and increasing exchange listings suggests that the altcoin market is poised for significant growth as September unfolds.
