Is an altcoin season starting soon? According to the Altcoin Season Index, an altcoin season usually kicks off when 75% of the top 50 coins outperform Bitcoin over the last 90 days. So far, only 11 of the top 50 coins have outperformed Bitcoin in the past 90 days. So, it looks like we're not there yet. But this could be the time to go down the risk curve and position yourself early.