The altcoin season may be approaching as momentum shifts in the cryptocurrency market. BTCD has sharply declined from over 65% to 63.89%, just as BTC crossed the $100,000 mark for the first time since 02/03.
This triggered a strong altcoin price surge, with Ethereum rising nearly 13% and major names like SOL, Doge, and ADA all increasing over 6%. Combined with the ETH/BTC ratio recovery from its 2020 low, this suggests a potential altcoin shift for the first time in months.
Altcoin Season Coming? Bitcoin Dominance Drops as ETH and Major Coins Surge
Bitcoin's dominance sharply dropped from over 65% to 63.89% within hours after BTC crossed the $100,000 mark for the first time since 02/03.
This change triggered a strong altcoin price surge, with Ethereum rising nearly 13% in 24 hours, while Solana (SOL), Dogecoin (Doge), and Cardano (ADA) all increased over 6%.
BTC Dominance (%). Source: TradingView.Until yesterday, Bitcoin's dominance reached its highest level since 01/2021, indicating BTC's superiority over the broader market in recent months.
Such a sudden reversal typically signals a capital shift, with traders beginning to move profits from BTC to altcoins. Recently, CryptoQuant's CEO, Ki Young Ju, called the Bitcoin Cycle Theory obsolete as TradFi gains prominence.
Adding to this story is the ETH/BTC ratio, which recently touched its lowest point since 2020—marking Ethereum's prolonged underperformance compared to Bitcoin.
ETH/BTC Ratio. Source: TradingView.A recovery from such historic lows could indicate the beginning of a structural shift favoring altcoins. If BTC's dominance continues to decline while ETH/BTC increases, it would be a strong signal that the market is transitioning to altcoin season.
With altcoin volume increasing and capital shifting to broader areas, May 2025 could mark the start of a major altcoin season.
May 2025: A Turning Point Towards Altcoin Season?
CoinMarketCap's Altcoin Season Index has increased from 23 to 36 in the past four days. This index tracks whether Bitcoin or altcoins are more dominant during a specific period.
An index below 25 indicates a "Bitcoin Season," where BTC outperforms most altcoins. Scores between 25 and 75 are considered neutral, while values above 75 officially signal an "Altcoin Season."
CMC Altcoin Season Index. Source: CoinMarketCap.The jump to the current neutral zone occurred after reaching a year-low of 12 in late April—the weakest point since December, when it peaked at 87.
CoinMarketCap's Altcoin Season Index measures whether at least 75% of the top 100 coins (excluding stablecoins and asset-backed tokens like WBTC and stETH) have outperformed Bitcoin in the past 90 days.
Top 18 Biggest Coins (YTD Performance). Source: Messari.YTD in 2025, Bitcoin has increased 10%—outperforming nearly all major altcoins except XRP, which has risen over 12%. Meanwhile, Ethereum remains down 30% YTD, and coins like LINK, Doge, AVAX, and SHIB are down over 20%.
Despite weak YTD performance, the sharp decline in BTC dominance, strong altcoin price surges in early May, and rising Altcoin Index all indicate that May 2025 could potentially begin a new altcoin season.
