A signal has emerged suggesting the altcoin market has entered a phase of relative strength versus bitcoin.

On Sept. 22, blockchain media outlet Cointelegraph reported that on-chain analytics firm Glassnode’s altcoin cycle indicator showed a new altseason signal this week.

The indicator assesses whether altcoins are leading by comparing market capitalisation flows between bitcoin and the top 250 cryptocurrencies. It classifies a period as an altseason when the market-cap growth rate of major altcoins excluding stablecoins temporarily becomes stronger than bitcoin’s. The detailed formula was not disclosed, but its seven-day moving average stood at 81.25 as of Sept. 22 on a normalised 0-100 scale.

Market trends also moved in a similar direction to the indicator. As bitcoin rose to $86,000 this week, total cryptocurrency market capitalisation recovered $3 trillion. Altcoin market capitalisation climbed to $1.19 trillion on Sept. 23, the highest level since late January. It is up 33% since Aug. 19.

Glassnode explained that during the first rebound in August only bitcoin rose while altcoins were flat, but this rebound has spread across the broader altcoin market.

Bitcoin’s overall market dominance, meanwhile, stayed in a narrow range without a clear additional rise. Bitcoin dominance edged up from 59.2% on Aug. 19 to 59.7% now. This suggests market funds are not concentrating only in bitcoin and are also spreading into altcoins.

Trader Matthew Hyland said a sense of complacency is emerging among bitcoin investors. He raised the possibility that bitcoin dominance may have already peaked on a macro level when it reached 66% in June 2025. He argued that investors are not accepting the reality that bitcoin has failed to make clear progress against altcoins since then.

Fund flows also leaned toward a recovery in risk appetite. Spot bitcoin exchange-traded funds recorded net inflows of about $999 million on Sept. 22, and spot ether ETFs took in $270 million. Both product groups posted their largest daily inflows since October 2025.

The overlap between bitcoin’s price level and the average purchase price of ETF investors is also drawing market attention. The overall average purchase price of spot bitcoin ETF investors was estimated to have formed just below $86,000 as of the end of last week. Bitcoin is now continuing attempts to establish that level as support.

Against this backdrop, the market’s next focus is whether altcoin strength will remain a short-term rebound or spread into a full rotation that leads to a decline in bitcoin dominance. So far, bitcoin’s rise, expanding altcoin market capitalisation and ETF inflows have appeared at the same time, showing risk appetite is reviving across the broader market.

The altcoin cycle signal has just flipped from bitcoin to altcoin season. The first rally in August saw altcoins stay relatively flat while BTC moved. However, today's rally has ignited the full breadth of the altcoin market. pic.twitter.com/vPf5lXiEUg