Altcoin Season Explodes in May 2025—Here’s Why Traders Are FOMOing In
Bitcoin dominance slips as ETH, SOL, and meme coins rally 50%+ in a week. The ’flippening’ chatter is back—but this time, altcoins aren’t just riding BTC’s coattails.
Key drivers: Layer-2 adoption surges, DeFi TVL hits $200B ATH, and yes, that inevitable ’dumb money’ wave from TradFi tourists chasing the next DOGE.
Warning signs? Always. Half these projects still have ’VP of Business Development’ LinkedIn bios longer than their actual codebase.
Altcoin Season Incoming? Bitcoin Dominance Dips as ETH and Majors Surge
Bitcoin dominance dropped sharply from over 65% to 63.89% in just a few hours after BTC surged past $100,000 for the first time since February 3.
This shift has sparked a strong altcoin rally, with Ethereum jumping nearly 13% in the last 24 hours, while Solana (SOL), Dogecoin (DOGE), and Cardano (ADA) each gained more than 6%.
Until yesterday, Bitcoin dominance was at its highest level since January 2021, showing how aggressively BTC outperformed the broader market in recent months.
A sudden reversal like this often signals a capital rotation, with traders beginning to shift profits from BTC into altcoins. Recently, CryptoQuant CEO Ki Young Ju called bitcoin Cycle Theory obsolete as TradFi takes over.
Adding to this narrative is the ETH/BTC ratio, which recently hit its lowest level since 2020—marking an extended Ethereum underperformance relative to Bitcoin.
A bounce from such historical lows could indicate the start of a structural shift favoring altcoins. If BTC dominance continues to fall while ETH/BTC rises, it WOULD be a strong signal that the market is transitioning into an altcoin season.
With altcoin volumes rising and capital rotating into broader sectors, May 2025 could begin a major altcoin season.
May 2025: A Turning Point Toward Altcoin Season?
The CoinMarketCap Altcoin Season Index has surged from 23 to 36 in the last four days. This index tracks whether Bitcoin or altcoins outperform over a specific period.
Readings below 25 indicate “Bitcoin Season,” where BTC outpaces most altcoins. Scores between 25 and 75 are considered neutral, while values above 75 officially signal “Altcoin Season.”
The current jump into neutral territory comes after reaching a yearly low of 12 in late April—its weakest point since December, when it peaked at 87.
The CMC 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 over the last 90 days.
So far in 2025, Bitcoin is up 10% year-to-date—outperforming nearly all major altcoins except XRP, which has gained over 12%. Meanwhile, Ethereum remains down 30% YTD, and coins like LINK, DOGE, AVAX, and SHIB have all dropped more than 20%.
Despite this weak YTD performance, the sharp drop in BTC dominance, strong altcoin rallies in early May, and the rising Altcoin Index all point to the possibility that May 2025 could begin a new altcoin season.
