What Are HODL Waves? Bitcoin Coin Age Bands Explained

The name comes from "HODL," the community term for holding through volatility. HODL waves turn that idea into a chart: instead of guessing whether people are holding or spending, you measure it directly from the age of every coin on the chain. Because a coin's age resets each time it moves, the distribution of ages across the whole supply is a fingerprint of collective behavior, and watching it shift over time tells you when holders accumulate and when they let go.

What are HODL waves?

HODL waves are a stacked band chart of the bitcoin supply grouped by coin age. Every coin falls into an age band based on how long it has sat unspent: under 24 hours, one day to a week, a week to a month, and on up to more than ten years. Each band is drawn as a wave, and the thickness of a wave at any point in time is the percentage of total supply in that age range. Stacked together, the bands always sum to 100 percent of the supply, so the chart shows how the whole supply is distributed across short-term and long-term holders at once.

How are HODL waves built?

The input is every coin's age, which is just the time since its output was created. For each day, bucket all unspent outputs into age bands, sum the coins in each band, and divide by total supply. Do that across history and the bands form the waves. The hard part is having every UTXO and its creation timestamp for every point in time, which requires a fully-indexed chain. A provider that already holds that can return the bands directly from a supply metrics API, so you rebuild the whole series without replaying the chain yourself.

What is the difference between HODL waves and realized-cap HODL waves?

Standard HODL waves weight each coin equally by count, so one coin is one coin regardless of when it last moved. Realized-cap HODL waves weight each band by realized value instead, using the price at which the coins in that band last moved. That shifts the emphasis toward the economic weight of each cohort rather than the raw coin count, which many analysts prefer because it ties the age bands to realized price and cost basis. Both views come from the same coin-age data; they just weight it differently.

These describe past behavior, not thresholds to trade on. Past patterns do not predict future prices.

How do you read HODL waves?

Read the older bands as the long-term-holder supply and the younger bands as recently moved coins. When the old bands swell, it means coins are sitting still and conviction is building, which tends to happen during accumulation. When old bands thin out and young bands swell, long-held coins are moving, which often lines up with distribution as older holders sell into strength. The metric shines at showing these slow shifts in holder patience that price alone hides. It is context about behavior that already happened, never a forecast.

Are HODL waves a trading signal?

No. HODL waves are an informational on-chain metric that describes how the supply is distributed by coin age. They are backward-looking and slow-moving by design, and analysts read them alongside supply in profit and loss, SOPR and exchange flows rather than as a standalone trigger. A single band moving does not tell you what price will do; it tells you how holders have been behaving. Treat it as one lens on the market, not advice.

How do you get HODL waves data?

You can build HODL waves yourself if you run a fully-indexed node and track the age of every UTXO at every point in history, then bucket and weight it. Most teams query it instead. Because BitcoinDatabase indexes every output and its creation timestamp in one schema, you can pull the current age-band breakdown over REST, rebuild the full HODL waves series in SQL, weight it by realized value, and trace any band back to the coins inside it. That keeps the chart auditable rather than a black box. Everything here is informational on-chain data and analytics, not investment advice.