PlanB (also written Plan₿) is a pseudonymous Dutch institutional investor and quantitative analyst who published “Modeling Bitcoin’s Value with Scarcity” in March 2019 — introducing the Bitcoin Stock-to-Flow (S2F) price model, which treats Bitcoin’s increasing scarcity (measured by the ratio of circulating supply to annual production) as the primary driver of its price, and projects exponentially rising valuations at each halving event; the model gained massive attention during the 2020–2021 bull run when Bitcoin tracked the model’s projections closely, and was subsequently challenged as Bitcoin failed to reach the S2F model’s $288,000 projection for the 2021 cycle.
Background and Identity
PlanB describes himself as a Dutch institutional investor with a law degree and master’s degree in quantitative finance who worked in traditional finance for over 20 years managing large asset portfolios. He began studying Bitcoin in 2018 and created the S2F model as a way to apply familiar financial analysis frameworks to Bitcoin. He has never revealed his identity, citing fears about asset seizure and privacy.
The Stock-to-Flow Model
Published on Medium on March 22, 2019, “Modeling Bitcoin’s Value with Scarcity” introduced the Bitcoin S2F model:
Stock-to-Flow (S2F) ratio:
$$text{SF} = frac{text{Stock (circulating supply)}}{text{Flow (annual production)}}$$
- Gold has an SF of ~60 (large stock accumulated over millennia; small annual production).
- Silver has an SF of ~22.
- Bitcoin’s SF increases at each halving:
Pre-2020 halving: SF ~25 (production 12.5 BTC/block × 144 blocks/day × 365 = ~656K BTC/yr)
Post-2020 halving: SF ~50 (production 6.25 BTC/block)
Post-2024 halving: SF ~120 (production 3.125 BTC/block)
The model’s key claim:
PlanB observed a statistically significant log-log correlation between Bitcoin’s SF ratio and its market capitalization across historical data points. The regression implied dramatically higher prices at higher SF ratios — projecting ~$55,000 per BTC post-2020 halving and ~$288,000 post-2024 halving based on the historical regression.
S2FX (Cross-Asset Model):
In 2020, PlanB extended the model to “S2FX” — comparing Bitcoin’s phase transitions (from collectible to store of value to financial asset) across different asset clusters, projecting even higher valuations.
Model Performance and Criticism
The S2F model had notable predictive accuracy during 2020–2021: Bitcoin’s price tracked the model’s “fair value” band through much of the bull run, contributing to the model’s popular credibility.
However, in 2021 and 2022:
- Bitcoin failed to reach the S2F model’s ~$100K+ projection for December 2021.
- Bitcoin subsequently fell to ~$16K in 2022 — far below model projections.
- Quantitative analysts including statistician Stephan Livera, economist Nic Carter, and researchers published criticisms of the model’s statistical methodology (spurious regression from non-stationary time series, data snooping bias).
PlanB has maintained that the model remains valid as a long-term framework, arguing that individual halving cycle projections may deviate while the long-run trend continues.
Key Dates
- 2018 — Begins studying Bitcoin; develops S2F concept.
- March 22, 2019 — Publishes “Modeling Bitcoin’s Value with Scarcity” on Medium.
- 2020 — Publishes S2FX (cross-asset) model extension.
- 2020–2021 — Model gains massive mainstream attention; Bitcoin tracks S2F band closely in 2020 phase.
- December 2021 — Bitcoin peaks at ~$69K, below S2F model’s ~$100K+ projection; criticism intensifies.
- 2022 — Bitcoin collapses to ~$16K; S2F model credibility significantly challenged.
- 2024 — Post-2024-halving cycle begins; PlanB continues publishing S2F updates.
Common Misconceptions
- “PlanB claims his model will be exactly right.” — PlanB has consistently framed S2F as a long-run price framework with wide confidence intervals, not a precise price prediction tool.
- “The S2F model is unique to Bitcoin.” — The stock-to-flow ratio is a standard commodity analysis metric; PlanB applied it to Bitcoin, but the metric itself is widely used in precious metals analysis.
- “PlanB works in crypto full-time.” — He has described himself as keeping his traditional institutional finance career during the model’s period of peak popularity.
Last updated: 2026-04