Direct Answer
Coin Days Destroyed (CDD) is an on-chain metric that weights every spent coin by how long it sat unmoved before that transaction, rather than counting each coin equally. Each unit of unspent output accumulates "coin days" for every day it holds still, and those accumulated coin days are "destroyed" the moment the coin is spent - so a single coin that had been dormant for years destroys far more coin-days in one move than thousands of coins that moved yesterday and are moving again today. Analysts use spikes in CDD as a signal that long-dormant supply, often associated with long-term holders, is becoming active.
Key Takeaways
- CDD = Number of Coins Spent × Days Since Last Moved, summed across every transaction in a period.
- Coin days accumulate while a coin sits unmoved and are "destroyed" (reset to zero) the instant it is spent.
- CDD weights old, dormant coins far more heavily than recently active ones, unlike a raw transaction count.
- A CDD spike signals that old supply moved on-chain - it does not by itself say why the coins moved.
- Analysts often read CDD alongside exchange inflow data before inferring intent to sell.
- A single large wallet consolidating an old balance can spike CDD without reflecting broad holder behavior.
- CDD underlies related dormancy-based metrics, including binary CDD and CDD-adjusted supply measures used by several on-chain data providers.
- CDD is best interpreted as a relative signal against its own recent trend, not against a fixed universal threshold.
What Is the Coin Days Destroyed Formula?
Coin Days Destroyed is calculated as:
CDD = Number of Coins Spent × Days Since Last Moved
This calculation happens at the level of an individual unspent transaction output (or, on account-based chains, an equivalent tracked balance). Each unit of that output accumulates one "coin day" for every full day it goes unspent - ten coins held untouched for six days have accumulated 60 coin days. The moment those ten coins are spent in a transaction, all 60 accumulated coin days are "destroyed" at once, and a fresh coin-day count starts for whatever new output(s) that transaction creates.
To get a period's total CDD (a day, a week, or any other window), an on-chain data provider sums the coin-days destroyed by every transaction that occurred within that window: Total CDD = Σ (Coins Spent × Days Since Last Moved) across all spending transactions in the period. Because the "days since last moved" term can vary from a single day to several years across different coins in the same period, this sum is dominated by whichever transactions moved the oldest coins, not by whichever transactions moved the most coins.
A Simple Illustration (Hypothetical Numbers)
The following example uses hypothetical, illustrative figures only - it does not reflect any real blockchain's actual transaction history. Suppose that on a given day, two separate transactions occur:
- Transaction A: 500 coins that had last moved 3 days earlier are spent. Coin days destroyed = 500 × 3 = 1,500 coin days.
- Transaction B: 5 coins that had last moved 900 days earlier (roughly two and a half years) are spent. Coin days destroyed = 5 × 900 = 4,500 coin days.
Even though Transaction A moved 100 times as many coins as Transaction B, Transaction B destroys three times as many coin days, because those five coins had been sitting untouched for far longer. Summed together, that day's total CDD is 1,500 + 4,500 = 6,000 coin days - and the majority of that total traces back to a small number of very old coins, not the larger, more recently active transaction. This is the core mechanic that makes CDD sensitive to old-coin movement in a way that raw transaction volume or transfer count is not.
Why Coin Days Destroyed Matters
Raw on-chain transaction volume treats a coin that last moved yesterday the same as a coin that last moved five years ago - both simply count as "one coin transferred." That makes volume a poor lens for distinguishing active, short-term trading activity from long-dormant supply becoming active again. CDD was designed specifically to close that gap: because it weights every spent coin by its holding age, a sudden increase in CDD is a signal that unusually old coins are moving, even if the total number of coins or dollar value transacted looks unremarkable.
Analysts often interpret a sustained rise in CDD as a sign that long-term holders - wallets that had been inactive through prior market cycles - are starting to move coins, which is sometimes read as early positioning to distribute or sell. Conversely, persistently low CDD relative to transaction volume suggests that most on-chain activity is coming from coins that have moved recently and repeatedly, which is more consistent with short-term trading, exchange or protocol activity, than with long-term holder behavior. CDD is one input among several dormancy-based metrics - including HODL waves and supply-in-profit measures - that analysts combine to build a fuller picture of holder behavior over a market cycle.
Limitations and Common Mistakes
- Doesn't reveal why coins moved. CDD only shows that old coins were spent, not the reason - an exchange deposit ahead of a sale, a custody or wallet-provider migration, an internal transfer between a holder's own wallets, and lost-key recovery can all produce the same spike.
- Single-wallet distortion. One whale, custodian, or exchange consolidating a large, old balance can produce a sharp CDD spike on its own, without reflecting any broader shift in holder sentiment across the network.
- Sensitive to a handful of very old coins. Because the weighting is multiplicative with age, a small number of ancient coins can dominate a period's total CDD far more than a much larger number of moderately old coins.
- No universal threshold. There is no fixed CDD level that signals "distribution" versus "normal activity" across all assets or market conditions - it must be read against its own recent trend.
- Reading in isolation. CDD is most useful alongside exchange net flows, realized-price metrics, and other dormancy indicators, not as a standalone buy or sell signal.
- Chain and methodology differences. Because "coin" and "unspent output" are defined differently across UTXO-based and account-based chains, CDD figures are not always directly comparable across different data providers or blockchains without checking their methodology.
Frequently Asked Questions
What is a good Coin Days Destroyed value?
There is no universal "good" or "bad" level - CDD is read as a relative signal, not an absolute score. Analysts typically compare a day's or week's CDD against its own recent baseline or moving average to spot unusual spikes, rather than judging any single reading in isolation.
How is Coin Days Destroyed different from simple transaction volume?
Transaction volume counts every coin moved equally, regardless of how long it sat still beforehand. CDD instead weights each spent coin by its holding age, so a coin that had been dormant for two years contributes far more to CDD than a coin that moved yesterday and is moving again today. This makes CDD more sensitive to old-coin movement than to raw transaction count or size.
Does a Coin Days Destroyed spike always mean holders are selling?
No. A spike only shows that old coins moved on-chain - it does not reveal the reason. Long-dormant coins can move because of an exchange deposit ahead of a sale, but also because of a custody change, wallet consolidation, an internal transfer, or lost-key recovery. CDD should be read alongside exchange flow data and other on-chain context before drawing a conclusion about intent.
Can one large wallet distort Coin Days Destroyed?
Yes. Because CDD is a sum across every spent coin in a period, a single whale or exchange wallet consolidating a large, old balance can produce a sharp spike on its own, even if the broader population of holders is inactive. Reviewing whether a spike traces back to one address versus many independent wallets is an important part of interpreting the metric.
How does a coin accumulate coin days?
One coin sitting unspent for one day accumulates one coin day, so the total accrues as the product of the amount held and the time held. When that holding is spent, all of its accumulated coin days are destroyed and counted for that day, and the coins begin accruing again from zero. This is why the metric responds to the age of what moved rather than to the quantity: a small amount of very old supply can destroy more coin days than a large amount of recently moved supply.
What are the supply-adjusted and binary variants of coin days destroyed?
Supply-adjusted coin days destroyed divides the raw figure by circulating supply, which allows comparison across a period in which supply grew substantially. Binary coin days destroyed compares each day's figure to a longer-run average and reports whether it exceeded it, converting a heavily skewed series into a simpler above or below reading. Both variants exist because the raw series spans orders of magnitude and grows with the chain, which makes any fixed threshold on it obsolete within a few years.
Does the coin day count reset for the recipient after a spend?
Yes. Once destroyed, the coin days are gone, and the outputs created by that transaction start accruing from that moment. The recipient's holding is treated as brand new regardless of how long the sender had held it. That is why a chain of transfers through several addresses destroys coin days on the first move and almost nothing on the subsequent ones, and why an entity restructuring its own wallets produces a single large destruction event followed by an artificially young holding.
Why is coin days destroyed usually plotted on a logarithmic scale?
Because the raw series is extremely skewed: most days are small and occasional days are larger by orders of magnitude, so on a linear axis every ordinary day is flattened against the baseline and only the spikes are visible. A logarithmic axis makes proportional changes across the ordinary range readable. The tradeoff is that a log axis visually compresses the spikes, which can make an exceptional event look routine, so the scale used should always be stated on the chart.
Can coin days destroyed be computed on an account-based chain?
Not in the same form, because the metric depends on identifying discrete units of supply with a known last-moved time, which the unspent output model provides directly. On an account chain a balance is a single number that is credited and debited, so there is no per-unit acquisition time to age. Providers construct approximations by applying an accounting convention such as first in, first out to an account's history, but the result is a modelled figure rather than a reading of chain state.
Related Reading
References
Coin Days Destroyed is a community-developed on-chain heuristic rather than a metric defined by a single official standards body or regulator. Methodology and exact calculation details can vary slightly between on-chain data providers - check a given provider's published methodology before comparing CDD figures across sources.
Disclaimer
This content is for educational purposes only and does not constitute investment, financial, tax, or legal advice. Swoopr Investment does not recommend any specific security, token, or trading strategy. On-chain metrics like Coin Days Destroyed describe historical blockchain activity and are one input among many - they do not predict future price movement and should not be used in isolation to make investment decisions. See our Financial Disclaimer for more information.