Total stored btc-days (+$-weighted) — Total stored coin age of the network (btc-days) + its dollar-weighted twin — dormant-conviction reservoir
Sum coin age examines the age structure of Bitcoin's unspent supply: Total stored btc-days (+$-weighted). It shows whether coins are maturing in wallets or being returned to circulation.
The network’s reservoir of stored conviction. Steady growth = dormant supply building; a visible dent = a large dormant tranche was spent.
Age bands are a lens on UTXOs, not on people. One holder can control many addresses, and a coin can move for reasons other than selling.