Altcoin Season Index Drops to 12, Bitcoin Dominance Surges

The Altcoin Season Index plummeted to 12 in June 2025, marking a historic low and underscoring Bitcoin's dominance in the market. This development signals a shift towards Bitcoin Season, a period where Bitcoin outperforms most alternative cryptocurrencies. Historically, the index has reached such lows in June each year since 2019, and June 2025 follows this cyclical pattern. Bitcoin's sustained strength has limited the momentum of altcoins, casting a shadow over their performance.

According to crypto analyst Michael van de Poppe, the Altcoin Season Index has crashed to a two-year low of 12, confirming Bitcoin Season conditions. This trend has been observed since August 2019, with red zones representing Bitcoin Seasons and blue zones reflecting periods where altcoins outperformed. Bitcoin dominance surged during bear markets in 2019, 2020, and 2022, while altcoins flourished during bull cycles, especially in late 2020 and throughout 2021. The current reading of 12 marks one of the lowest levels since inception, confirming that Bitcoin now leads the market decisively.

The market's focus has shifted back to Bitcoin amid uncertainty and fading altcoin narratives. This suggests traders prefer the perceived safety and liquidity of BTC. Furthermore, failed breakouts in major altcoins support this shift, reflecting investor hesitation. Despite weak altcoin performance, the total crypto market capitalization is strong. It now stands at $3.087 trillion after gaining $31.3 billion in a single day. Notably, the market has reclaimed and backtested a two-year ascending trendline, offering technical support.

The chart features resistance zones that previously acted as ceilings during the 2021 bull run. However, the current consolidation near all-time highs suggests resilience, not weakness. Consequently, while Bitcoin outpaces altcoins, the crypto market expands. Altcoin underperformance reflects relative positioning rather than fundamental collapse. Historical data implies that deep Bitcoin dominance phases often precede altcoin rebounds.