Bitcoin HHI Supply Concentration Index Hits 1116.1 on July 21, Highest Since December 2021

According to monitoring by Axel Adler Jr, Bitcoin's HHI (Herfindahl-Hirschman Index) supply concentration index reached 1116.1 on July 21, the highest level since December 2021. The reading exceeds 89.6% of historical observations over the past decade.

The index rose 5.5% over the past 90 days and 10.1% over the past 180 days, driven primarily by coins held in the 6-12 month holder cohort, which increased from 12.9% to 19.3% of supply over 90 days. The shift reflects natural coin-age progression rather than new accumulation, with 81.6% of Bitcoin supply now unmoved for over six months.