Glossary / Markets & investing
Coin days destroyed
Also known as CDD.
- Definition
- Coin days destroyed weights every spend by how long the coins had been sitting still, so one bitcoin untouched for 100 days destroys 100 coin days when it moves.
Raw transaction volume treats a coin shuffled ten times an hour the same as a coin untouched since 2011, and this metric does not. The idea appeared on the Bitcointalk forum in 2011, long before the analytics industry that now sells it. What it detects is old money waking up, the kind of supply that tends to arrive late in a rally.
How it works
Every coin accumulates one coin day for each day it sits unspent, and spending it destroys the accumulated total.
The arithmetic is per input. Five bitcoin last moved 400 days ago destroy 2,000 coin days. Five bitcoin received yesterday destroy 5. Add up every input in every transaction in a block and you have that block's contribution; add up the blocks and you have the daily figure. With roughly 20 million coins in existence, the network as a whole accrues about 20 million fresh coin days every day, and only spending burns them off.
Several variants exist because the raw number grows with the supply. Supply-adjusted versions divide by circulating supply. Binary coin days destroyed reduces each day to a yes or no answer about whether it exceeded the yearly average, which makes clusters of old-coin movement easier to see. The value days destroyed multiple compares recent destruction with its own longer-run average.
The concept has an older cousin inside Bitcoin Core itself. Early versions computed a transaction's priority from coin age, multiplying each input's value by the number of confirmations it had, and reserved a slice of every block for high-priority transactions that paid no fee. Bitcoin Core removed that code in version 0.15.0, released in September 2017. Coin age survives as an analytics idea rather than as anything the software does.
Where you see it
Spikes in coin days destroyed are the standard alarm for dormant supply becoming liquid.
The interesting cases are large and rare. Mt. Gox began distributing recovered bitcoin to creditors in July 2024, moving coins that had been frozen since the exchange failed in February 2014, and the resulting destruction dwarfed ordinary trading activity. Government seizures reaching the market do the same thing. So do estates being settled and exchanges rebuilding cold storage.
That last point is the caveat. Destruction tells you old coins moved; it cannot tell you why. A custodian re-keying its vaults produces the same signature as a decade-old holder selling, and analytics firms distinguish them by guessing at address clusters. Treat a spike as a question rather than an answer.
The useful reading for a buyer is unglamorous. Sustained low destruction means long-term holders are sitting still. Repeated heavy destruction into a rising price means supply that has been off the market for years is being handed to newer buyers, which is a real thing to know, and is still not a reason to change what you do this month if you buy on a schedule.