Altcoin Season Index falls to 21, down 4 points

CoinMarketCap's Altcoin Season Index has fallen four points from yesterday to 21. The index determines market sentiment by comparing the performance of the top 100 cryptocurrencies, excluding stablecoins and wrapped tokens, against Bitcoin over the last 90 days. An "altcoin season" is declared when 75% of these top altcoins outperform Bitcoin during that period. A reading closer to 100 indicates a stronger altcoin season, while a lower number suggests a "Bitcoin season."