Understanding the Bitcoin Stock-to-Flow Price Model

The stock-to-flow (S2F) model is a valuation framework for Bitcoin that suggests the cryptocurrency’s long-term price movements are primarily driven by its inherent scarcity [1]. Created by a pseudonymous Dutch analyst known as PlanB, the model posits that as the supply of Bitcoin is restricted through periodic "halving" events, the asset’s price should see increasingly higher peaks every four years [1].

Key takeaways

• The S2F model calculates value by dividing Bitcoin’s total supply, or "stock," by its annual production, or "flow" [1].
• PlanB claims the model remains valid as long as Bitcoin’s price stays within one standard deviation of the projected range, which he estimates between $50,000 and $200,000 [1].
• Critics of the model have questioned its reliability after Bitcoin failed to reach a specific $100,000 target by the end of 2021 [1].
• The model’s creator acknowledges that external "black swan" events, such as geopolitical crises or regulatory bans, could potentially invalidate his forecasts [1].

The mechanics and limitations of scarcity-based forecasting

The S2F model operates on the principle that because only 21 million bitcoins will ever exist, the reduction of mining rewards—which occurs roughly every four years—creates a predictable scarcity that influences market cycles [1]. Historically, this pattern appeared to align with price rallies observed in 2013, 2017, and 2021 [1]. While Bitcoin reached a record high of nearly $69,000 in November 2021, it fell short of the $100,000 point estimate that some had anticipated for the end of that year [1].

In response to the price discrepancy, PlanB has argued that the model should be viewed as a range estimate rather than a precise price target [1]. He maintains that because the price remained within the model's standard deviation bands, the framework remains "intact" and useful for his own analysis [1]. However, this shift in interpretation has drawn skepticism from some observers, with critics suggesting that the model’s parameters are being adjusted to account for its failure to hit specific price milestones [1].

External factors and market uncertainty

While the S2F model focuses on internal supply dynamics, market experts note that broader macroeconomic conditions also play a significant role in Bitcoin's performance [1]. Factors such as inflation, central bank policies, and the ongoing impact of the Covid-19 pandemic have been cited as potential headwinds that could cause the cryptocurrency to struggle regardless of its supply schedule [1].

PlanB has consistently cautioned that his model is not immune to external shocks [1]. He has previously identified "black swan" events—including government-led Bitcoin bans, major escalations in public health crises, or geopolitical conflicts—as variables that could fundamentally disrupt the projected price trajectory [1].