Axel Adler Jr said Bitcoin's supply concentration index, or HHI, reached 1,116.1 as of July 21, above 89.6% of historical readings over the past decade. According to Odaily, the index rose 5.5% over the past 90 days and 10.1% over the past 180 days.
Bitcoin's supply distribution has continued to become less even, with holdings concentrated among specific holding-period groups. Adler said the increase was driven mainly by coins held for 6 to 12 months, whose share rose from 12.9% to 19.3% over the past 90 days, while the share of coins held for 3 to 6 months fell from 14.3% to 6.3%. Coins held for more than 10 years accounted for 17.7% of the total.
He said the change reflected the natural aging of existing coins and a shift from the 3- to 6-month holding period to the 6- to 12-month range, rather than a new round of large-scale accumulation. He added that 81.6% of Bitcoin supply has not moved for more than six months, and 62.3% has been idle for more than one year.