This FAQ covers everything you need to know about Plan B's bitcoin stock-to-flow (S2F) model, its predictions, criticisms, and its impact on Bitcoin's price narrative. It is designed to give you clear, factual answers to the most common questions surrounding this controversial yet influential framework.

What is Plan B's bitcoin stock-to-flow model?

The Plan B stock-to-flow (S2F) model is a bitcoin price forecasting framework that uses the ratio of existing bitcoin supply (stock) to newly produced bitcoin (flow) to predict future prices. It is based on the idea that bitcoin's scarcity, as measured by this ratio, is a primary driver of its market value. The model was popularized by the pseudonymous Dutch analyst Plan B in 2019.

Specifically, the S2F model draws an analogy to precious metals like gold and silver, which have high stock-to-flow ratios due to their slow annual production relative to existing supply. Plan B's model plots historical bitcoin prices against its S2F ratio and finds a strong logarithmic correlation, which he then uses to project future price targets. The model has been both highly praised for its early accuracy and heavily criticized for its simplistic assumptions and vulnerability to overfitting.

Who is Plan B in the bitcoin community?

Plan B is the pseudonymous creator of the bitcoin stock-to-flow model, a Dutch investor and former institutional asset manager who has become a prominent figure in the bitcoin community. He first introduced the S2F model in a March 2019 Medium article, and it quickly gained widespread attention for its bold price predictions and seemingly strong historical fit.

Despite his anonymity, Plan B has maintained an active presence on Twitter (now X) and his website, sharing model updates and engaging with both supporters and critics. His work has been instrumental in popularizing the idea that bitcoin's scarcity is a fundamental value driver. However, his exact identity remains unknown, which has added an element of mystery and also drawn criticism regarding accountability for the model's failures.

How accurate have Plan B's bitcoin price predictions been?

Plan B's stock-to-flow model has had a mixed track record of accuracy, with some early predictions hitting close to the mark but later ones missing significantly. For example, the model's prediction for the 2021 bull cycle called for a peak around $100,000, but bitcoin actually peaked at about $69,000 in November 2021, a notable shortfall. Earlier, the model's projection for 2020 was around $10,000, which proved roughly accurate.

The model's biggest failure came in 2022, when it predicted an average price of $100,000 for the year, but bitcoin instead ended the year around $16,000, a dramatic deviation. This has led many to question the model's reliability, especially for short-term predictions. It's important to note that the S2F model is a long-term valuation framework, not a day-trading tool, and its predictive power is based on historical correlations that may not hold in the future.

Why is the stock-to-flow model controversial?

The stock-to-flow model is controversial because it relies on a simplistic correlation that may not be causation, and it has been criticized for cherry-picking data and lacking fundamental economic underpinnings. Critics argue that the model's apparent accuracy before 2020 was partly due to overfitting, and that it fails to account for changes in market dynamics, adoption rates, and macroeconomic factors.

Furthermore, the model's creator Plan B has been accused of moving the goalposts when predictions fail, and the model has not been peer-reviewed in a formal academic sense. Supporters, however, point to the model's early success and its logical basis in scarcity. The controversy highlights a broader debate in the bitcoin community between those who favor quantitative models and those who emphasize more qualitative or on-chain analysis.

What are the main criticisms of Plan B's bitcoin model?

The main criticisms of Plan B's stock-to-flow model include its reliance on a single variable, its lack of a causal mechanism, and its poor performance in recent years. The model effectively ignores demand-side factors, such as adoption rates, regulatory changes, and macroeconomic conditions, which can have a major impact on price.

Additionally, the model's statistical methodology has been questioned, with some researchers showing that the correlation between stock-to-flow and price may be spurious or the result of data mining. The model also fails to account for bitcoin's halving cycles in a nuanced way, treating them as purely supply-side events. Despite these criticisms, the model remains popular because it offers a simple, intuitive narrative for bitcoin's long-term value, and it has been instrumental in attracting institutional interest.

Can Plan B's stock-to-flow model predict bitcoin's future price?

No, the stock-to-flow model cannot reliably predict bitcoin's future price with certainty, as it is based on historical correlations that have already broken down. The model predicted a $100,000 average price for 2022, but bitcoin ended the year around $16,000, a massive error. This demonstrates that the model is not a robust forecasting tool for short-term or even medium-term price movements.

However, some proponents argue that the model may still hold value as a long-term valuation metric, suggesting that bitcoin could eventually reach high prices if its adoption continues to grow. But the model's predictive failures, especially after 2021, have significantly undermined its credibility. It is generally advisable to view the S2F model as one of many analytical frameworks, not as a definitive price oracle.

What is Plan B's latest bitcoin prediction for 2026?

As of early 2026, Plan B has not publicly issued a specific price prediction for 2026, but his stock-to-flow model implies a range that aligns with an expected post-halving bull market. The S2F model's projections for 2024-2028 (the current halving cycle) suggested an average price of around $550,000 for the period, though he has also mentioned a potential peak of up to $1 million in some interviews.

However, it's crucial to note that these figures are derived from a model that has already failed to meet its past targets. Plan B has acknowledged the need to adapt the model and has hinted at incorporating additional factors. As of now, there is no official, updated prediction for 2026, so any numbers circulating online are speculative and should be treated with caution.

What are the pros and cons of using the stock-to-flow model for bitcoin?

The pros of using the stock-to-flow model include its simplicity, its strong historical fit, and its ability to frame bitcoin's scarcity as a key value driver. It has also helped bring attention to bitcoin's unique supply dynamics and has been a useful tool for long-term investors to conceptualize potential price appreciation.

The cons are significant: the model has a poor recent track record, it ignores demand-side factors, and it can lead to overconfident investment decisions. Critics also point out that the model's correlation may be spurious, and that it fails to account for black swan events or regulatory changes. Ultimately, the S2F model should be used with caution and in conjunction with other forms of analysis, such as on-chain metrics and fundamental valuation, rather than as a standalone predictor.

Final Thoughts

Plan B's bitcoin stock-to-flow model has been one of the most discussed and debated price forecasting tools in the cryptocurrency space. It brought a simple, compelling narrative to bitcoin's value proposition, but its predictive failures, especially after 2021, have highlighted the dangers of relying on any single quantitative model in a highly volatile and evolving market.

As we move through 2026, it's important to approach such models with a critical eye. While they can provide useful frameworks for understanding long-term trends, they should never be used as the sole basis for investment decisions. Always combine multiple sources of data, stay informed about market developments, and be prepared for a wide range of possible outcomes.

In summary, the S2F model remains a fascinating case study in crypto analytics, but its track record suggests that no model can perfectly predict the future. Whether you are a believer or a skeptic, understanding the model and its limitations is essential for anyone looking to navigate the complex world of bitcoin investing.