Is the Altcoin Season Starting in September? Two Charts Hold the Answer

An altcoin season is typically signaled by a decline in Bitcoin dominance. Recent data shows Bitcoin dominance rising, while the ETH/BTC ratio has surged to a 7‑month high, creating mixed signals for a potential altcoin rally.

ETH/BTC Ratio Breaks Out

The ETH/BTC pair broke out of a long‑term descending channel, reaching approximately 0.0334, the highest level since January 2026. The breakout occurred at the end of June and has held above the channel since. Resistance is now at 0.03213 (the 0.382 Fibonacci level), with the next barrier at 0.03426. Support sits around 0.031, which aligns with the April 2026 swing high for Ethereum against Bitcoin.

Bitcoin Dominance Rises Above 60%

Bitcoin dominance closed the previous week at 60.15%, breaking a descending trendline from June 2025 and moving above the upper boundary of a recent triangle pattern. The metric gained 0.91% for the week. Resistance is near 60.50%, while support is at 58.54% with stronger support at 58%.

Altcoin Season Index Declines

The Altcoin Season Index, which measures how many of the top 50 coins have outperformed Bitcoin over 90 days, fell to 39 from roughly 67 in early August. A reading of 75 is typically required to signal an altcoin season, indicating current conditions are not supportive of a broad rotation.

Derivatives Indicate Altcoin Optimism

Glassnode reported that 85% of altcoins now have funding rates above their mean, the highest level since Bitcoin reached record highs. This suggests heightened optimism among altcoin traders, even though spot returns still lag Bitcoin.

Possible Scenarios

• A weekly close above 0.03426 on ETH/BTC combined with a rejection at 60.50% dominance could confirm a genuine rotation into altcoins.
• A dominance break above 60.50% while the ETH/BTC ratio stalls would point to an Ethereum‑focused rally.
• A drop below 0.031 would indicate the recent moves were a temporary bounce.