Epoch Supply Breakdown
BTC supply decomposed across the five halving eras (50 / 25 / 12.5 / 6.25 / 3.125 BTC). Each era's cohort accumulates supply from its block subsidy and is held independently - the stacked layers visualise the structural age of total circulating BTC.
What is it?
This metric decomposes Bitcoin's total circulating supply by the halving era in which each UTXO was mined. Five cohorts emerge: Era 50 BTC (genesis 2009 → halving 1 late 2012), Era 25 BTC (halving 1 → halving 2 mid-2016), Era 12.5 BTC (halving 2 → halving 3 mid-2020), Era 6.25 BTC (halving 3 → halving 4 mid-2024), Era 3.125 BTC (halving 4 → halving 5 estimated). The sum of all five layers equals the total circulating supply at any date. An era's cohort only grows during that era and then remains static (unless coins from that era are spent and redistributed to the active era).
How to read
The Y axis shows absolute BTC values stacked. Bottom layer = oldest era (Era 50 BTC). Top layer = most recent era (Era 3.125 BTC, growing). Transitions between eras are marked by halvings (alternating colors). A contracting layer indicates that its cohort is distributing (UTXOs spent toward a younger era). A stable layer indicates a strongly hibernating cohort.
Key zones
The active subsidy era grows mechanically (~144 blocks/day × block subsidy). The historical cohort (Era 50 BTC + Era 25 BTC) represents the bulk of long-duration holdings - it acts as a structural baseline. Visible distributions from older eras toward the active era typically mark large-scale redistribution phases.
What to observe
Track the relative dominance of layers: if the active era's cohort rapidly overtakes the older layers, the market is redistributing heavily. Conversely, a consolidation of the historical cohort (older layers stable) at a cycle low indicates multi-cycle holders are not capitulating. The vertical marker of each halving delineates the temporal boundary at which a new cohort is introduced.
Historical context
The concept of halving-era cohorts emerges from Bitcoin's distinct monetary nature: block subsidy is halved every 210,000 blocks (~4 years). Each era thus has a 'generation' of UTXOs whose average issuance price, hodl depth and behavioral profile differ structurally. The first systematic analyses by halving cohort appear in the on-chain literature post-2017, when enough full cycles became available for comparison.
Expert notes
The epoch_* cohorts exposed here are deterministic aggregates computed from the Bitcoin full node (sum of UTXOs filtered by issuance block height). This is a documented exception to SOP §1.2 'no pre-computed ratio', justified by the non-ambiguous nature of cohort aggregation (atomic sum, not composite ratio). Trinity's consistency audit (TAE chain step 6 RECOMPUTE_C) compares these cohorts to total supply to catch any drift.
Common mistakes to avoid
Do not confuse this metric with Halving Cycle ROI (`halving-cycle-roi`) which measures annualized price return per era, nor with Reward Era Compare (`reward-era-compare`) which compares cycle progress position. The present metric focuses solely on supply decomposition by issuance era, not valuation. A decreasing layer does not indicate 'loss' - spent UTXOs are simply reclassified into the active era's cohort at spend time.
Programmatic access
REST API
curl -sS \
'https://api.trinityinsights.io/api/v1/onchain/epoch-supply-breakdown/history?days=90' \
-H 'X-API-Key: $TRINITY_API_KEY'MCP server
{
"tool": "get_chart_value",
"metric_id": "epoch-supply-breakdown",
"timeframe": "1y"
}Required tier: free. See the pricing grid for the tier list and the MCP documentation for multi-client configuration.
Related metrics
Institutional disclaimer
Trinity Insights is an educational and analytical tool. The metric above does not constitute investment advice. Trinity Insights is not a Crypto-Asset Service Provider (CASP) registered under MiCA Regulation (EU) 2023/1114. See the full disclaimer.