Altcoin Season Index Climbs To 37 Indicating Rotation Away From Bitcoin

TLDR:

• Market: The CoinMarketCap Altcoin Season Index rose from 34 to 37 on August 13th, 2025, which means that 37 out of the top 100 digital assets by their market cap performed better than Bitcoin in their last 90 days.
• Narrative: The rise in the index signals a move toward altcoins, or the idea that investors are more attracted to currencies outside of Bitcoin. Although still not at 75 for an all-time altcoin season, the direction is positive for rising speculative possibilities in the crypto market.

The altcoin market is recovering as the CoinMarketCap Altcoin Season Index increased to 37 on 13 August 2025 from 34 at one point earlier in the day. As a real-time metric that monitors the performance of 100 large-cap altcoins versus Bitcoin across 90 days, this reading indicates that 37 out of this group of coins have outperformed their counterpart in Bitcoin, and this is proof of a shift in sentiment in the markets. Although this reading is short of 75, which would be a fully-fledged altcoin season, this rise is bullish for surging interest among investors in their respective counterparts in altcoins, which creates speculative opportunities within the crypto universe.

With the Altcoin Season Index at 37, what this means is that money is flowing out of Bitcoin and into other coins, driven by multiple stories of the market. Unlike in the event of an entire altcoin season, where 75 or more altcoins would outperform Bitcoin, what is actually occurring shows a transitional process, where Bitcoin remains dominant to a great degree. The direction of this index reflects immediate sentiment, where it considers the performance of leading altcoins on a 90-day rotation cycle.

Risks, however, are that trailing data of this index does not predict future tendencies, and previous altcoin spikes have often led to rapid correction. For investors who are tracking expanding altcoin momentum, this increase in this index gives a glimpse of likely opportunities, but caution must be exercised in this volatile market.