Altcoin season has officially started as the Altcoin Season Index reached 78. This index is a tool that shows when altcoins are stronger than Bitcoin. When the index is above 75, traders say altseason has begun. In past years like 2017 and 2021, this number meant altcoins rallied for weeks. Now in 2025, the same signal has appeared again, and many believe altcoins could see big gains soon. Bitcoin dominance has slipped below 49.5%, which means Bitcoin controls less of the crypto market. As Bitcoin’s share falls, money often flows into altcoins, including Ethereum and many mid-cap tokens. Some of these coins are already showing daily gains of 40%, which matches what happened in past altcoin rallies.
The Altcoin Season Index compares how many altcoins outperform Bitcoin over 90 days. If 75% or more are doing better than Bitcoin, then the index moves above 75. That number now sits at 78, which is the highest level in eight months. Analysts on X, like BitBull and CryptoJack, point to this as proof that altcoin season is here. They remind traders that every time the index crosses this level, altcoins begin to lead the market. This is happening even though Bitcoin’s price has stayed steady for months between $60,000 and $65,000. Bitcoin price stability gives space for altcoins to shine because investors look for higher returns elsewhere.
Another reason altcoins are rising is the golden cross. A golden cross happens when a short-term moving average goes above a long-term moving average on a chart. Traders view this as a bullish sign that prices could climb higher. In 2017 and 2021, golden crosses led to massive altcoin rallies where some coins grew thousands of percent. Analysts like Master of Crypto believe the same pattern is repeating now. The golden cross is showing up again, and altcoins are reacting with fast growth. This gives traders confidence that history may repeat and altcoins could see explosive moves in the coming weeks.
Bitcoin dominance also shows a bear flag, which is a bearish chart pattern. Trader Tardigrade explained that a bear flag in Bitcoin’s dominance often signals more declines in its market share. Each time Bitcoin loses ground, altcoins pick it up. In this cycle, capital is rotating out of Bitcoin and into Ethereum and mid-cap coins. Investors who avoided risk before are now more willing to enter altcoins. Recent lower U.S. inflation data and comments from the Federal Reserve about easier policy have made risk assets like crypto more attractive again. This macro backdrop supports the shift into altcoins and adds strength to the current altseason.
Ethereum is also playing a larger role. Its market share is growing as new liquidity enters decentralized finance. ETH dominance rising is a strong sign because Ethereum often leads other altcoins higher. Mid-cap names are also benefiting. These coins are smaller than Bitcoin and Ethereum but large enough to attract institutional money. They can move quickly during altcoin season and reward traders with big short-term gains. Many of these altcoins have already started to double in value, and the altcoin market cap shows signs of breaking out. If this continues, the total market cap of altcoins could double from current levels before the end of the year.
The Altcoin Season Index is not the only signal traders use, but it is one of the most reliable. By comparing many altcoins to Bitcoin, it shows when the market favors risk-taking. With the index now above 78, analysts call this the official start of altseason. Combined with a golden cross, fading Bitcoin dominance, and strong demand for mid-cap altcoins, the setup looks similar to past bull runs. Traders who follow these patterns say they see the same cycle repeating. They believe altcoins may soon reach levels last seen in 2021. If that happens, this altseason could mark one of the biggest rallies in recent history.
For people new to crypto, altcoin season means a shift in focus from Bitcoin to the wider market. Bitcoin remains the first and largest cryptocurrency, but it does not always deliver the highest gains. During altseason, coins like Ethereum, Solana, Avalanche, and other mid-caps can take the spotlight. This is what many call the rotation of capital. It reflects how traders move their money when Bitcoin dominance falls and the Altcoin Season Index rises. The mix of technical signals like the golden cross and bear flag, combined with macro shifts from the Federal Reserve, has created the conditions for this change. Altcoins now have a chance to lead again, and the numbers suggest the cycle is just getting started.
