Cohort HODL Strength (150D)
Percent of each halving-epoch cohort's Bitcoin supply still unspent, aligned on days since onboarding — a cross-cycle survival view of holder conviction.
What is it?
For each halving epoch we define a cohort: the set of coins 'onboarded' (created on-chain) within an accumulation window around the halving — by default 99 days before the halving (the gap from the IBIT spot-ETF launch on 11 January 2024 to the 2024 halving) then a 150-day onboarding window. We then track the fraction of that cohort still unspent over time via a Kaplan-Meier survival curve S(t) = N(t)/N₀, where N₀ is the cohort size at the window's close. The horizontal axis is not a calendar date but the number of days since onboarding, which lets the cycles be overlaid and compared 'at the same age'.
How to read
Each curve is one epoch (cycle) cohort. A curve that stays high indicates strong conviction: buyers from that window keep their coins. A curve that falls quickly indicates early distribution. Because every cohort starts at 100% on day 0 and is aligned on days post-onboarding, you read directly which generation of buyers held longest. The overlaid BTC price line (log scale) places each trajectory in its market context.
Key zones
Three retention thresholds frame the reading: above 50% still unspent, the cohort retains solid health; between 25% and 50%, conviction weakens; below 10%, nearly the whole cohort has changed hands (capitulation or full profit-taking). These zones are age-relative: a cohort at 50% after 1,000 days is far more convinced than one at 50% after 100 days.
What to observe
Watch divergences between cohorts at the same age: a cycle whose curve dominates the previous ones indicates a stickier holder base. Also watch slope breaks — an acceleration of the decline marks a distribution phase. Compare the in-progress cohort (the youngest, still incomplete) to the historical cohorts at the same number of days post-onboarding to place current conviction in context.
Historical context
The method applies to the cohorts of the 2012, 2016, 2020 and 2024 halvings. The 2009-2012 cohort is hidden by default: early supply was too small for a stable denominator, and Bitcoin had no market price before mid-2010. Historically, cohorts onboarded near a cycle low have shown more durable retention than those onboarded during full euphoria.
Expert notes
The Kaplan-Meier survival estimator is borrowed from medical survival analysis; applied to UTXOs there is no within-window censoring (all on-chain spends are observed), so S(t) = N(t)/N₀ exactly. The conceptual lineage traces back to HODL Waves (Unchained Capital, 2018) and age-band decomposition. The onboarding windows sit on age-band edges, which makes N₀ exact; the curve's tail is interpolated beyond the fine 30-day edges.
Common mistakes to avoid
'Still unspent' does not mean 'held forever': lost keys or passive institutional custody inflate retention without active conviction. The cohort is a UTXO proxy: it includes coinbase, change outputs and exchange-internal moves. Finally, the in-progress cohort is right-censored to the same horizon as the youngest epoch to stay comparable — its curve is not 'worse', it is simply shorter.
Programmatic access
REST API
curl -sS \
'https://api.trinityinsights.io/api/v1/onchain/cohort-hodl-strength-150d/history?days=90' \
-H 'X-API-Key: $TRINITY_API_KEY'MCP server
{
"tool": "get_chart_value",
"metric_id": "cohort-hodl-strength-150d",
"timeframe": "1y"
}Required tier: free. See the pricing grid for the tier list and the MCP documentation for multi-client configuration.
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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.