Bitcoin News Today: Bitcoin's 45% Wall Stands as Altcoin Season Index Nears 76

Bitcoin's price exceeding $120,000 has sparked renewed debate about the dynamics of on-chain demand and the potential for an extended altcoin season. Recent data indicates a shift in capital allocation, with Bitcoin's market dominance (BTC.D) declining to 56.81% as of October 4, 2025, breaking below the descending triangle support on its daily chart. This decline, coupled with the Altcoin Season Index reaching 76-the highest since December 2024-suggests a growing rotation of capital into altcoins. The index, which measures the performance of top altcoins relative to Bitcoin, officially signals "altcoin season" when it exceeds 75, a threshold now firmly within reach.

Ethereum (ETH) has emerged as a pivotal player in this transition. The ETH/BTC ratio, a key indicator of altcoin strength, has surged to 0.040, breaking above the upper trendline of a bullish pennant. Meanwhile, Ethereum's dominance over Bitcoin has intensified, with the token outperforming BTC by 21.9% in Q3 2025 compared to Bitcoin's 13.85% gain. Technical indicators such as the Chaikin Money Flow (CMF) and MACD for ETH/BTC show strengthening momentum, reinforcing the likelihood of a broader altcoin rally.

Market liquidity factors also support the case for an altcoin-driven phase. The Federal Reserve's potential 25-basis-point rate cut this week could inject fresh capital into risk assets, historically favoring altcoins over Bitcoin. Additionally, the total altcoin market cap (excluding Bitcoin) has risen to $1.7 trillion, with the Moving Average Convergence Divergence (MACD) forming a bullish crossover on the daily chart. Analysts project that if this trend persists, the altcoin market could reach $2.3 trillion, driven by sustained buying pressure and favorable macroeconomic conditions.

However, risks remain. Bitcoin's dominance has not yet fallen below the critical 45% threshold typically associated with altcoin seasons, and historical patterns show that previous altcoin surges have often corrected within weeks. For instance, the 2024 altcoin season, marked by a 76 index reading, saw sharp corrections despite initial gains. Moreover, the Altcoin Season Index currently stands at 51, indicating a transitional phase rather than full-blown altcoin dominance.

The role of Ethereum as a catalyst is further underscored by its ecosystem activity. Institutional demand for ETH has surged, with entities like Bitmine Immersion Technologies purchasing 1.15 million ETH and funds holding 3 million ETH, representing over 2% of the global supply. Tokens tied to Ethereum, such as Arbitrum and Ethena, have also seen substantial gains, with Lido's staked ETH (STETH) rising 58% monthly. These developments align with broader narratives around real-world assets (RWAs) and stablecoin adoption, which could prolong the current altcoin momentum.

Investors are advised to monitor key thresholds. If Bitcoin dominance continues to decline and the Altcoin Season Index surpasses 75, a prolonged altcoin season could materialize, mirroring the 2021 cycle where the altcoin market cap reached $1.71 trillion. Conversely, a reversal in BTC.D or a Fed decision to avoid rate cuts could curtail the rally. For now, the interplay between Bitcoin's resilience and altcoin innovation suggests a market in flux, with Ethereum positioned as the linchpin for the next phase of crypto growth.

Source: [1] Altcoin Season Confirmed After Nearly a Year as Crypto Market Cap Smashes $4T (https://www.ccn.com/analysis/crypto/altcoin-season-confirmed-crypto-market-cap-smashes-4t/)

[2] Altcoin Market Cap Soars as Coinbase Eyes Q3 Breakout (https://beincrypto.com/coinbase-predicts-altcoin-season-as-q3-2025-approaches/)

[3] BTC/ETH Breakdown and RSI Signal Potential Early Signs of Altseason Rotation (https://en.coinotag.com/btc-eth-breakdown-and-rsi-signal-potential-early-signs-of-altseason-rotation/)

[4] Altcoin Season Index Steady: Bitcoin Trends to Watch (https://coinedition.com/altcoin-vs-bitcoin-what-the-2025-index-tells-us-now/)

[5] Altcoin Season 2025 Will Be Bigger Than 2021 - Here's Why (https://coinpedia.org/news/altcoin-season-2025-will-be-bigger-than-2021-heres-why/)

[6] Ethereum vs Bitcoin War Begins: ETH Leads Q3 With (https://www.coingabbar.com/en/crypto-currency-news/ethereum-vs-bitcoin-q3-altseason-2025-performance-shift)

[7] Altcoin Season Index: Is it Altseason right now? - Blockchaincenter (https://www.blockchaincenter.net/en/altcoin-season-index/)

[8] Altcoin Statistics (2025) – Usage, Volume & Market Insights (https://www.demandsage.com/altcoin-statistics/)

[9] Alt Season Indicators - Real-Time Crypto Market Analysis Dashboard (https://www.thealtsignal.com/)

[10] Crypto Market Cap Charts - TVL, Altcoins (https://www.tradingview.com/markets/cryptocurrencies/global-charts/)

[11] Altcoin Season Index | CoinMarketCap (https://coinmarketcap.com/charts/altcoin-season-index/)

[12] Bitcoin Dominance Drops, But 2025 Altcoin Season (https://www.ccn.com/analysis/crypto/bitcoin-dominance-declines-altcoin-season-doubt/)