The 2025 cycle has introduced some notable market differences.
Historically Bitcoin [BTC] has seen strong rallies after each halving, with the first four post-halving cycles driven by supply shortages and demand imbalances. However, this trend was broken in 2025, with BTC ending the year with a loss of 6%.
A similar difference occurs with altcoins. TOTAL3 (market cap ex-BTC and ETH) has printed its fourth consecutive red year against Bitcoin, effectively ending an “altcoin season” that has been fading for four years.
Source: TradingView (TOTAL3/BTC)
That difference obviously points to BTC’s growing market influence.
Technically this is not a stretch. Bitcoin dominance (BTC.D) has achieved four consecutive upward trends, from roughly 40% in 2022 to over 60% in 2025. That’s a solid 100% increase in market cap, adding roughly $900 billion.
Notably, over the same period, the total market capitalization grew to $1.11 trillion, meaning almost 80% of that new capital ended up in BTC, highlighting its growing influence. Is an altseason in this context really a thing of the past?
The 2021 Rally in Hindsight: Key Altcoin Market Signals
Looking back, the 2021 cycle was a by-the-book altcoin season.
The twelve-month chart shows The market capitalization of BTC ended the year up 64%, breaking the historic $1 trillion mark. And yet TOTAL3 (market cap ex-BTC and ETH) completely surpassed this, by a whopping 541%.
The result? The Altcoin Season Index spiked, heralding a full altseason, with capital clearly rotating into the broader alt market. However, BTC has since taken control. The question is: what has really changed?
Source: TradingView (TOTAL3)
The answer is simple: Altcoin financing rates have increased.
Simply put, leveraged longs are overcrowded, and while that may sound bullish, altcoins are actually caught in a volatile loop. Even a small sideways move can trigger a cascade of liquidations.
Add to that the rising BTC.D and alts have become very vulnerable to sharp swings. In this context, the growing gap between Bitcoin and alts is no coincidence. Instead, it shows why 2021 was probably the last true “altcoin season.”
Final thoughts
- Altcoin funding rates have risen, creating crowded longs that are trapping altcoins in a volatile loop.
- Increasing Bitcoin dominance has funneled capital into BTC, leaving alts vulnerable and explaining why 2021 was likely the last true “altcoin season.”