What is the Altcoin Season Index?

The Altcoin Season Index compares the 90-day performance of the top 100 coins with bitcoin's, using our own price history. Stablecoins and wrapped versions of the same asset are left out.

• A high reading means most large altcoins beat bitcoin over the period: altcoin season.
• A low reading means bitcoin outperformed most of them: bitcoin season.

The index and bitcoin dominance are shown on the homepage and on Global.