According to CoinMarketCap (CMC) data, the CMC Altcoin Season Index currently stands at 40, reflecting a increase of 2 points compared to the previous day. The index measures market performance by analyzing the top 100 cryptocurrencies by market capitalization. Over the past 90 days, 40 of these altcoins have outperformed Bitcoin in terms of price growth. The CMC Altcoin Season Index is used to determine whether the current cryptocurrency market is in an altcoin-dominated season. It is based on the performance of the top 100 altcoins relative to Bitcoin over the past 90 days.