Bitcoin AHR999 Index
The AHR999 index multiplies two ratios: the Bitcoin price over its 200-day cost (the geometric mean of the last 200 daily closes) and the price over a growth-model price fitted to Bitcoin's age in days. Its author treated readings below 0.45 as unusually cheap and 0.45–1.2 as a range for regular buying. The chart shows every day's value on a log scale.
On 29 Sep 2026 the AHR999 index is 0.56: Bitcoin ($83,866) is 1.18× its 200-day geometric-mean cost ($70,869) and 0.47× the growth-model price for coin age 6,478 days ($177,343). That is between 0.45 and 1.2. Since 4 Mar 2018 the index was below 0.45 on 17% of days and above 1.2 on 28%. Its lowest reading in this data was 0.22 on 12 Mar 2020 and its highest 9.34 on 21 Feb 2021.
Source: Binance spot BTCUSDT daily closes (UTC), from 17 Aug 2017Chart 17 Aug 2017 – 29 Sep 2026As of 09:29 UTC