What is the Stock-to-Flow Model in Crypto?

Last Updated 2026/07/06

Scarcity-Based Valuation: The Stock-to-Flow (S2F) model estimates Bitcoin's value by comparing its existing supply (stock) to its annual issuance (flow).

Halving-Driven Framework: Bitcoin's periodic halving events reduce new supply and significantly increase its S2F ratio, forming the foundation of the model.

Digital Gold Thesis: S2F treats Bitcoin as a scarce monetary asset, similar to gold, and argues that increasing scarcity should support long-term value appreciation.

Historical Influence: The model gained prominence after accurately tracking Bitcoin's price growth during earlier market cycles, particularly between 2019 and 2021.

Not a Complete Forecasting Tool: Critics argue that S2F overlooks demand, market sentiment, regulation, and macroeconomic factors that heavily influence Bitcoin's price.

Best Used with Other Indicators: Many investors combine S2F with on-chain metrics, technical analysis, and risk management tools rather than relying on it alone.

In the world of digital assets, valuation frameworks often borrow from traditional finance to make sense of price behavior. Among these, the Stock-to-Flow (S2F) model stands out as one of the most discussed — and most debated — tools for understanding Bitcoin's long-term value. Originally applied to commodities like gold and silver, the model was adapted for Bitcoin by the pseudonymous analyst PlanB in his seminal 2019 Medium article titled "Modeling Bitcoin Value with Scarcity," drawing parallels between Bitcoin and traditional commodities like gold and silver. The premise is simple: the scarcer an asset becomes, the more valuable it should be.

For Bitcoin investors on platforms like KuCoin, the S2F model offers a lens through which to view the asset's predictable supply schedule and the implications of halving events that occur roughly every four years. Yet, despite its early predictive success, the model has also faced significant criticism for ignoring demand-side factors and over-relying on scarcity alone.

To classify the unique characteristics of the Stock-to-Flow model, we apply the 6W framework:

Who: Long-term Bitcoin investors, on-chain analysts, and macro-focused traders who treat BTC as a scarce digital commodity.
What: A quantitative valuation framework that estimates Bitcoin's price based on the ratio of existing supply (stock) to annual new issuance (flow).
Why: To translate Bitcoin's hard-coded scarcity into a price expectation, similar to how gold and silver have historically been valued.
Where: Applied primarily to Bitcoin, occasionally extended to other fixed-supply assets; tracked through public charts and on-chain dashboards.
When: Most relevant around halving events, when Bitcoin's flow is mechanically cut by 50%, doubling the S2F ratio.
How: By dividing total circulating supply by annual production and fitting the resulting ratio to a regression that projects long-term price.

The Stock-to-Flow model measures how scarce an asset is by comparing its existing supply against its annual production. The stock-to-flow model measures how scarce an asset is by dividing its total existing supply (stock) by how much new supply is produced each year (flow). The ratio tells you how many years of current production would be required to replicate the existing stock.

A high S2F ratio means an asset is very scarce because relatively little new supply is created each year compared to the existing stock. Gold, for example, has a stock-to-flow ratio typically fluctuates around 60–70, meaning it would take roughly 60 years of mining at current rates to reproduce the existing supply. Silver sits lower, and most industrial commodities — which are consumed rather than stored — have ratios close to zero.

The model's underlying logic is intuitive: when production is small relative to existing supply, new issuance has limited impact on price, and the asset's value is dominated by its perceived scarcity. This makes S2F a natural framework for monetary commodities — assets whose value derives largely from their store-of-value properties rather than industrial demand.

Bitcoin is uniquely suited to S2F analysis because its supply schedule is hard-coded into its protocol and visible to every participant. That predictability is Bitcoin's defining advantage for S2F analysis. Gold mining responds to price signals and geological constraints. Bitcoin's schedule is hardcoded and visible to everyone.

To calculate Bitcoin's current S2F ratio, two numbers are required. First, the stock — the total number of BTC mined to date. As of 2026, approximately 19.7 million BTC have been mined into existence. The blockchain records this transparently - there's no estimation involved.

Second, the annual flow. After the April 2024 bitcoin halving, each successfully mined block rewards miners with 3.125 BTC. With roughly 144 blocks mined per day (one every ~10 minutes), annual issuance comes out to roughly 164,250 new BTC per year. Dividing stock by flow gives a current ratio of roughly 120 — placing Bitcoin's scarcity profile above gold for the first time in its history.

The model uses the formula: Price = 0.18 × (S/F)^3.3, which has historically shown a 95% correlation with Bitcoin's last traded price movements. This power-law relationship is what generates the upward-sloping price projection line seen on most S2F charts.

Halvings are the engine that drives the S2F model's price projections. Each Bitcoin halving cuts the block reward - and therefore the annual flow - by exactly 50%. With flow halved while stock continues to grow, the S2F ratio approximately doubles post-halving.

The 2020 halving pushed the ratio from ~26 to ~56; the 2024 halving pushed it from ~56 to ~113-120. The S2F model interprets this as a mechanically-driven scarcity event that structurally increases Bitcoin's value proposition. Halvings are pre-programmed to occur every 210,000 blocks - making them the only major supply shock in financial history that can be predicted with near-certainty years ahead of time.

Historical halving cycles have produced significant price appreciation, although the magnitude has diminished with each cycle. Historical data shows a pattern of bull cycles with diminishing, yet still powerful, amplitudes: 2012 Halving: US $12 → US $1,150 (8,858 % gain, peak after 367 days) 2016 Halving: US $650 → US $20,000 (3,000 % gain, peak after 526 days) 2020 Halving: US $8,590 → US $69,000 (700 % gain, peak after 547 days)

This pattern is central to the S2F thesis. As each halving cuts new issuance, the model predicts a new equilibrium price level — though the time required to reach it, and whether the model still holds, has become increasingly contested.

The S2F model's enduring popularity comes from several genuine strengths.

Simplicity and accessibility. A common criticism against Bitcoin S2F is that it's overly simplistic, but the straightforward nature of this model makes it accessible to a broad audience in the crypto space. By quantifying the relationship between Bitcoin's current supply and projected issuance in a scannable chart, PlanB made it relatively easy for market analysts to get a quick read on Bitcoin's scarcity and perceived value.

Grounded in verifiable fundamentals. Another strength of the S2F model is its emphasis on fundamental aspects of Bitcoin's tokenomics rather than abstract theories. By concentrating on Bitcoin's scarcity, halving schedule, and fixed supply, this model avoids printing out subjective valuations and unsubstantiated speculative claims.

Halving event predictability. The model has demonstrated notable accuracy in predicting price movements surrounding Bitcoin's halving events. By quantifying the supply shock created by these programmatic reductions in mining rewards, investors can anticipate potential price catalysts and plan their investment strategies accordingly.

Historical correlation. Between 2019 and mid-2021, its accuracy bordered on prophetic, correctly tracking Bitcoin's rise from US $10,000 to US $60,000. Several academic studies noted a 95 % correlation between S2F ratios and price, with gold and silver falling neatly along the same regression line.

Long-term framework. For investors committed to long-term Bitcoin accumulation, the Stock-to-Flow Model provides a strategic framework that extends beyond short-term volatility. It encourages a patient investment approach by highlighting the relationship between decreasing supply and potential price appreciation over multi-year periods.

The S2F model has also drawn substantial criticism, especially after its predictions diverged sharply from actual prices in late 2021.

Ignores demand entirely. A critical weakness is the model's treatment of demand as constant. The Stock-to-Flow Model focuses exclusively on supply-side economics while largely ignoring demand fluctuations. In reality, Bitcoin demand can vary dramatically based on adoption rates, regulatory environment, competition from other cryptocurrencies, and macroeconomic conditions.

Major predictive failures. Then came December 2021 — S2F's public reckoning. PlanB's "floor model" predicted US $98,000 for November and US $135,000 for December. Bitcoin instead closed at roughly US $47,000, missing the mark by more than half. The failure was so stark that PlanB temporarily declared the model "invalidated."

The divergence has only widened in subsequent years. Bitcoin was trading around $71,000 as of March 10, 2026, far below the roughly $500,000 average price projection for the 2024–2028 cycle implied by the S2F model. The discrepancy has fueled discussion among market participants over whether the model signals a major rally ahead or has lost relevance as crypto markets mature.

Black swan blind spot. Black swan events, regulatory crackdowns, or major security breaches can dramatically affect Bitcoin's price in ways the model cannot predict.

Bear market bias. The model has been criticized for potentially failing during prolonged bear markets. It tends to present optimistic price projections that may not materialize when market sentiment turns decisively negative or when broader economic conditions deteriorate significantly.

Over-reliance on the "digital gold" framing. Another significant criticism involves the model's implicit assumption that Bitcoin functions as "digital gold." While this narrative has gained traction, it remains unproven whether Bitcoin will achieve precious metal status in global finance. Furthermore, this commodity-focused perspective neglects Bitcoin's other value propositions such as peer-to-peer payments or its role as a potential reserve asset.

Academic skepticism. Notable figures including Ethereum co-founder Vitalik Buterin have publicly criticized the model. Back in June 2022, Buterin posted: "Stock-to-flow is really not looking good now. I know it's impolite to gloat and all that, but I think financial models that give people a false sense of certainty and predestination that number-will-go-up are harmful and deserve all the mockery they get,"

Peer-reviewed research has reached similar conclusions. The stock-to-flow model predictions and Metcalfe's Law help to explain Bitcoin's returns in-sample but have limited to no ability to predict Bitcoin's returns out-of-sample. In contrast, Bitcoin market sentiment and technical analysis measures are generally unrelated to Bitcoin's returns in-sample and are poor predictors of Bitcoin's returns out-of-sample.

Despite its limitations, the S2F model can still play a useful role when combined with other analytical tools. Most practitioners now treat it as one input among many rather than a standalone forecasting engine.

Pair with on-chain demand metrics. The MVRV Z-Score and the Mayer Multiple are commonly used alongside S2F. According to on-chain data as of early 2026, Bitcoin's MVRV Z-Score sits at 1.32 - well below the overheated zone above 7. Used together: S2F for the macro supply context, MVRV for market participant behavior, Mayer Multiple for price momentum. That's a significantly more complete picture than any single model provides.

Treat it as a directional compass, not a price target. The S2F model is a compass, not a GPS. Useful for orientation. Insufficient for precise navigation. Master that distinction, and it becomes a genuinely powerful tool in your analytical stack.

Account for structural demand shifts. When institutional trading venues are included, Coinbase Advanced holds the largest balance, with roughly 800,000 BTC, though that figure has fallen by about 200,000 BTC since July 2025. The steady decline in exchange reserves could have significant implications for Bitcoin's price. When fewer coins are held on exchanges, the tradable supply available to meet immediate demand shrinks, potentially amplifying price movements if buying pressure rises.

Maintain rigorous risk management. Manage Your Risks: Understand the risks associated with relying on a single model. The S2F model, like any predictive model, has limitations and uncertainties. Set clear risk management rules for your investments, including stop-loss orders and position sizing.

The Stock-to-Flow model represents one of the most influential attempts to quantify Bitcoin's value through the lens of scarcity. By dividing Bitcoin's existing supply by its annual issuance and fitting that ratio to a price regression, PlanB created a framework that resonated deeply with investors who view Bitcoin as digital gold. Through the 2020-2021 cycle, the model's near-95% historical correlation gave it an almost prophetic reputation.

However, the model's failures since late 2021 have made clear that scarcity alone cannot explain price. Demand-side dynamics — institutional adoption, ETF flows, macroeconomic conditions, regulatory shifts, and competitive pressure from other assets — all influence Bitcoin's value in ways the S2F model is structurally incapable of capturing.

For investors using KuCoin, the most balanced approach is to treat the S2F model as a long-term directional reference rather than a precise price predictor. Combining it with on-chain demand metrics, macro analysis, and disciplined risk management produces a far more complete view of Bitcoin's value than any single framework can offer. Scarcity matters — but so does everything else.

Q1: What is a good Stock-to-Flow ratio for Bitcoin?

After the April 2024 halving, Bitcoin's S2F ratio rose to roughly 113-120, placing it above gold's typical ratio of 60-70. A higher ratio implies greater scarcity, but it does not automatically translate into a higher price.

Q2: Is the Stock-to-Flow model still accurate in 2026?

The model's predictive accuracy has deteriorated significantly since 2021. By 2025, the model has largely become defunct. Despite its ultimate failure as a price predictor, the S2F model's lasting legacy is arguably a positive one. Its greatest contribution was providing a simple, powerful, and intuitive framework that helped millions of people grasp Bitcoin's best qualities of being a verifiable and scarce digital asset.

Q3: Can the Stock-to-Flow model be applied to other cryptocurrencies?

The model is most meaningful for assets with fixed or highly predictable supply schedules. Bitcoin fits best because of its hard cap of 21 million coins and pre-programmed halvings. Assets with flexible monetary policies or unlimited supply do not produce meaningful S2F ratios.

Q4: What is the difference between the S2F and S2FX models?

The original S2F model uses only Bitcoin's stock-to-flow ratio. The S2FX (Cross Asset) variant adds market capitalization data and groups Bitcoin into distinct phases of development, allowing comparisons with how gold and silver matured as monetary assets over time.

Q5: Should beginners rely on the Stock-to-Flow model?

Beginners should treat the S2F model as one educational lens for understanding Bitcoin's scarcity, not as a standalone investment guide. Pairing it with on-chain metrics, macro analysis, and disciplined risk management produces far more reliable decisions than following any single model.

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