Altcoin Season Back? Blockchaincenter Declares It, While CMC Data Disagrees

According to blockchaincenter.net’s Altcoin Season Index (ASI), the gauge has now flipped to the notorious altcoin season. While this tracker signals it’s game time for altcoin assets, coinmarketcap.com’s ASI tool insists the market hasn’t reached that point just yet.

Altcoin Season Alert: 76% Score on Blockchaincenter’s ASI While Bitcoin Dominance Slides

Both trackers agree on one rule: if 75% of the top 50 coins outperform bitcoin over the past 90 days, it officially qualifies as altcoin season. At 4 p.m. Eastern on Sept. 11, 2025, blockchaincenter.net’s ASI flashed “it’s altcoin season” with a score of 76 out of 100.

Blockchaincenter’s ASI on Sept. 11, 2025. Data from the past 90 days highlights hefty gains across multiple cryptocurrencies, led by PENGU’s staggering 235.4%. CRO notched a 179.1% rise, while IP and ENA advanced 164.6% and 155%, respectively. MNT climbed 148.6%, and SEI added 80.1%. Chainlink (LINK) increased 77.5%, with ethereum ( ETH) up 70.4%.

Blockchaincenter’s ASI on Sept. 11, 2025. Other standouts include WLD gaining 61.8%, ARB up 51.5%, solana ( SOL) rising 49.6%, avalanche (AVAX) adding 48.5%, stellar ( XLM) up 47.8%, hedera (HBAR) climbing 47.1%, and XRP finishing with a 43.5% boost.

Coinmarketcap.com’s ASI data on Sept. 11, 2025. Coinmarketcap.com’s (CMC) ASI figures register a score of 66 out of 100, with a wider mix of tokens making the 90-day leaderboard. MYX stole the show with a staggering 17,423.43% rally, trailed by M at 2,747.81% and OKB at 277.84%.

CMC’s dataset diverges slightly on percentage gains, even for overlapping coins. Despite blockchaincenter.net’s ASI declaring it altcoin season, the streak may be short-lived. Since the extended run in 2021, most altcoin seasons have only appeared as fleeting bursts.

Crypto supporters have quickly picked up on the shift, with xAI’s Grok highlighting dozens of X posts buzzing about the high score. Whether this move develops into something lasting or fades as another quick burst remains to be seen.

At the same time, the ticker is above 75 on blockchaincenter.net’s ASI and a 66 on CMC’s, bitcoin’s dominance remains under the 60% range at 58.22%.