Definition
Coin Days Destroyed (CDD) is an on-chain metric that weights the movement of coins by how long they sat unspent. Each coin accumulates one coin-day for every day it remains dormant in an unspent transaction output (UTXO); when it is finally spent, those accumulated coin-days are considered destroyed. The metric is calculated by multiplying the quantity of coins moved by the number of days each had been held, then summing across all transactions in a period.
Why dormancy is weighted
Plain transaction volume treats a coin that just moved and a coin held for five years identically. CDD does not. By giving older coins proportionally more weight, it emphasizes activity by long-dormant supply, often associated with experienced, long-term holders, over the high-frequency churn of recently moved coins. A coin held one year that moves destroys roughly 365 coin-days; the same coin moved after a day destroys just one.
How it is interpreted
A sharp spike in CDD signals that significant old supply has moved, which can indicate long-held coins being spent or repositioned. Sustained low CDD indicates that older holdings are staying put. Related derivatives include dormancy (CDD divided by transaction volume) and supply-adjusted CDD, which normalizes the figure against total circulating supply for cross-cycle comparison.
This entry is educational and not trading advice. CDD is built from the age and value of spent outputs, so it pairs naturally with HODL Waves and the broader UTXO data model.
In Simple Terms
Coin Days Destroyed (CDD) is an on-chain metric that weights the movement of coins by how long they sat unspent. Each coin accumulates one coin-day…