On September 11, 2025, Blockchaincenter.net’s Altcoin Season Index (ASI) officially turned to “altcoin season” with a score of 76 out of 100. However, CoinMarketCap’s (CMC) similar tool registers only a 66, indicating the market has not yet met the threshold for an official altcoin season. Both indices share the same rule: altcoin season is declared when 75% of the top 50 coins outperform Bitcoin over the past 90 days. While Blockchaincenter’s gauge turns green, CMC data remains cautious.
90-Day Gainers: Meme Coins and Old-School L1s Surge
According to Blockchaincenter, multiple cryptocurrencies posted massive gains in the past 90 days. PENGU led with a staggering 235.4%, followed by CRO at 179.1%, IP at 164.6%, and ENA at 155%. MNT climbed 148.6%, SEI rose 80.1%, Chainlink (LINK) gained 77.5%, and Ethereum (ETH) advanced 70.4%. Other notables include WLD (61.8%), ARB (51.5%), Solana (SOL, 49.6%), Avalanche (AVAX, 48.5%), Stellar (XLM, 47.8%), Hedera (HBAR, 47.1%), and XRP (43.5%).
Notably, CMC’s list differs due to its own methodology. MYX surged an extraordinary 17,423.43%, M rose 2,747.81%, and OKB gained 277.84%. Even for overlapping coins, the percentage changes diverge slightly between the two platforms.
Bitcoin Dominance Falls Below 60% — How Long Will Altcoin Season Last?
Despite the indicator disagreement, Bitcoin dominance (BTC.D) has dropped to 58.22%, slipping below the key 60% level. Historically, most altcoin season signals since the prolonged 2021 run have been short-lived bursts. The community on X (formerly Twitter) is buzzing, with xAI’s Grok highlighting dozens of posts discussing the high score. Whether this move develops into a lasting trend or fades as another quick surge remains to be seen.