Bitcoin Stock-to-Flow in 2026: A $500K Model, a $64K Market

On the morning of August 19, 2026, one Bitcoin traded at $64,339, down about 43% from a year earlier and worth roughly half of the record above $125,000 it set in October 2025. The most famous scarcity model in crypto says that number is a rounding error on the way to something far larger. On the current reading of PlanB’s Stock-to-Flow framework, the 2024 to 2028 halving cycle should average close to $500,000 per coin. The distance between that promise and a $64,000 market is the whole story of this article.

For a stretch running from 2019 into 2021, Stock-to-Flow (usually shortened to S2F) looked like the closest thing digital assets had to a law of physics. A single chart, drawn from the same scarcity math used to value gold and silver, seemed to explain where Bitcoin had been and to predict where it was headed. Traders pinned its colored bands to their screens. Newsletters treated its price targets as a timetable rather than a guess. Then the model broke, in public, and it did so more than once.

This is a full accounting of that break. It covers what the model actually claims, why it spread so fast, the specific price calls it missed, the statistics that never really supported it, and why, in a market now reshaped by spot exchange-traded funds and the SEC, a chart built only on supply keeps printing numbers Bitcoin will not touch. The point is not that scarcity does not matter. The point is that scarcity, on its own, was never enough.

What the Stock-to-Flow Model Actually Claims

Stock-to-flow is an old idea borrowed from commodities analysis. The stock is the total amount of something that already exists. The flow is how much new supply gets produced each year. Divide the first by the second and you get the number of years it would take, at today’s production rate, to recreate the entire existing pile. A high ratio means new supply is tiny next to what is already above ground, which is the technical definition of a hard, scarce asset.

Gold is the classic example. The world holds a large hoard relative to what miners dig up in any given year, which gives gold a stock-to-flow ratio somewhere around 62. Silver sits near 22. The pitch behind the model is simple: assets that are hard to produce tend to hold value, and the ratio puts a number on that hardness.

Bitcoin fits the frame almost too neatly. Its supply schedule is written into the code. Roughly every four years the reward paid to miners for each block is cut in half, an event called the halving. Each halving slashes the flow of new coins while the stock keeps climbing, so Bitcoin’s stock-to-flow ratio doubles at a stroke. PlanB’s leap was to argue that this rising ratio does not merely describe Bitcoin’s scarcity; it sets Bitcoin’s price, on a tight mathematical curve, for years at a time.

Who Is PlanB, and How a Medium Post Went Viral

The model belongs to an anonymous analyst who publishes under the handle PlanB and the account 100trillionUSD. He describes himself as a Dutch institutional investor with a background in quantitative finance, and he has never revealed who he is. In March 2019 he posted an essay titled Modeling Bitcoin’s Value with Scarcity, and it spread across crypto Twitter within days.

The essay’s power came from one image: a scatter plot of Bitcoin’s monthly stock-to-flow ratio against its market value, with a regression line running through it. The dots hugged the line. PlanB reported an R-squared of about 95%, a figure that, taken at face value, suggested scarcity explained almost all of Bitcoin’s price history. In a field starved for anything that looked like rigor, that number landed like a revelation.

From there the model compounded. PlanB turned the regression into forward price targets, then into monthly floor prices, then into a grander cross-asset version that folded gold and silver into the same equation. Each version traveled further than the last. By 2021, S2F had become shorthand for the bull case, and PlanB had built one of the largest followings in the market on the strength of a single chart.

The Math: Turning Scarcity Into a Price

To see why the model looked so convincing, and where it hides its weakness, watch the ratio move. Before the May 2020 halving, miners produced about 657,000 new coins a year against a stock of roughly 18 million, for a ratio near 27. The 2020 halving cut annual issuance to about 328,500 coins and pushed the ratio to around 56. The April 2024 halving cut it again, lifting Bitcoin’s stock-to-flow above 100 and, on paper, into the neighborhood of gold.

The model’s engine is a power-law regression that maps this ratio onto a market value, then divides by the coin supply to get a price. Because the ratio roughly doubles at every halving, the fitted price does not rise in a straight line; it steps up in large jumps every four years. That is the source of both the model’s appeal and its most eye-watering forecasts. Feed a stock-to-flow of 56 into the equation and it returns a six-figure Bitcoin. Feed it 120 and it returns something closer to half a million dollars.

Notice what is missing from every input. There is no term for demand, no term for adoption, no term for interest rates, exchange failures, regulation, or the cost of the power that secures the network. The only variable that moves the output is scarcity. The model treats supply as destiny.

The Predictions, From $55,000 to $288,000

The first forecasts were, by the standard of what came later, almost modest. The 2019 model implied a Bitcoin market value near $1 trillion, or roughly $55,000 per coin, once the 2020 halving lifted the ratio to 56. For a while, reality cooperated: Bitcoin cleared a $1 trillion market value and traded well above $55,000 in early 2021, and the model’s defenders took a victory lap.

Then the targets escalated. In April 2020, PlanB published the Stock-to-Flow Cross Asset model, or S2FX, which treated gold, silver, and two phases of Bitcoin as points on a single regression. That version implied a Bitcoin market value around $5.5 trillion and an average price of $288,000 for the 2020 to 2024 cycle. The forecast nearly tripled overnight, and it did so on the strength of adding two extra data points to a curve.

The pattern in that table is the tell. The model’s cheapest, earliest target got hit. Every target that required Bitcoin to keep climbing at the pace scarcity demanded got missed, and the misses grew wider as the numbers grew larger.

The Floor Model and a Promise That Got Walked Back

The most concrete test PlanB ever set for himself was the floor model. In 2021 he published a series of monthly worst-case prices, levels Bitcoin supposedly would not close beneath if the model held. The sequence ran $47,000 for August, $43,000 for September, $63,000 for October, $98,000 for November, and $135,000 for December.

For three months it worked. Bitcoin closed August and September almost exactly on the marked floors and came within a couple thousand dollars in October. Then November arrived and Bitcoin, instead of pressing toward $98,000, drifted lower and closed the month around $57,000. December was worse; rather than reaching a $135,000 floor, Bitcoin ended the year near $47,000, roughly a third of the promised level.

What makes the episode sting is what PlanB had said on the way up. In June 2021 he wrote that he would call S2F invalidated if Bitcoin had not reached $100,000 by December that year. When December came and went with Bitcoin nowhere near six figures, that line collided with reality. His response was to reframe rather than retire the model. On December 18 he shrugged that he actually liked being at the lower bands. A week later he drew a careful line: a “FLOOR MODEL FAIL” was real, he conceded, but the core S2F model, he insisted, remained “INTACT.”

That split, floor model dead but core model alive, is the maneuver critics point to most often. It let the forecast keep its aura while quietly detaching from the specific, falsifiable numbers that had made it famous.

June 2022: Falling Through the Floor

If late 2021 bruised the model, 2022 buried it. The S2F chart does not draw a single line; it draws a band, with the fitted value in the middle and colored zones above and below. For most of the model’s life, Bitcoin had stayed inside that band. On June 18, 2022, it dropped clean through the bottom of it for the first time, and it kept going.

The backdrop was brutal. The Terra ecosystem had imploded in May, erasing tens of billions of dollars in weeks. Central banks were raising interest rates at the fastest pace in decades, draining the cheap money that had lifted every risk asset. Then, in November, the exchange FTX collapsed and Bitcoin fell to about $15,500, its lowest level in two years. Not one of those forces appears anywhere in a stock-to-flow equation, because none of them touches supply.

The collapse drew a sharp public rebuke from Ethereum co-founder Vitalik Buterin. On June 21, 2022, days after Bitcoin fell through the lower band, Buterin wrote that “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.” He did not name S2F, but no one in the timeline had to ask what he meant.

PlanB’s answer was that his critics were opportunists, looking for something to blame after a crash they had not seen coming. The exchange captured the whole debate in miniature: one camp saw a broken model, the other saw a broken market that would eventually snap back to the model. Which of those you believed in the summer of 2022 said a lot about how you would trade the next two years.

The Statistical Case Against Stock-to-Flow

The market’s verdict is one thing. The statistics were arguably the bigger problem, and they were flashing red long before the 2022 crash. The core objection is that the model’s headline correlation is, in the technical sense, spurious.

Here is the mechanism. Bitcoin’s stock-to-flow ratio rises over time in a near-deterministic staircase, because the halvings are pre-scheduled. Bitcoin’s market value has also risen over time. Regress one steadily rising series against another and you will almost always get a beautiful R-squared, whether or not the two things are causally linked. It is the same trap that lets you prove ice cream sales cause drownings, since both climb in summer. A 95% fit between two variables that both trend up with time is close to meaningless on its own.

The formal version of the complaint centers on cointegration, a test for whether two trending series share a genuine long-run relationship or just drift upward together. The economist and analyst Alex Kruger laid it out in 2020, warning that the model rested on the wrong assumption that there is cointegration between price and scarcity, and that without it, using stock-to-flow to predict price is, in his words, nonsensical. He went further, calling the model based on the most fundamental errors, which in his view rendered it absolutely useless.

Kruger was not alone. The analyst Nick Emblow, who had initially defended the model precisely because he thought it showed a valid cointegrating relationship, later reversed course and concluded the correlation was effectively spurious once the data was tested properly. Researcher Eric Wall catalogued a long list of ways the fit fell apart under scrutiny, including the awkward fact that regressing Bitcoin’s market cap against its stock-to-flow ratio partly regresses the coin’s own stock against itself. Neutral explainers of the model, including CoinGecko’s, now list these statistical problems as standard caveats.

Kruger also flagged a softer but corrosive issue: the targets were open-ended enough that a believer could always keep pushing the deadline until the price finally cooperated. A forecast that can slide its own goalposts is hard to falsify, and a claim that cannot be falsified is not much of a prediction.

The Efficient Market Problem

There is a deeper objection that needs no regression at all. Bitcoin’s supply schedule is public. Everyone knows, to the block, when each halving will occur and exactly how much the flow will drop. If cutting supply on a known date reliably sent the price to a known level, rational traders would simply buy ahead of the event and capture the move in advance. That buying would pull the future gain into the present, and the neat post-halving step in the S2F chart would smear out into noise.

In other words, a scarcity that is fully known in advance should already be priced in. This is the efficient-market critique, and it cuts at the model’s foundation. For S2F to keep working, the market would have to be perpetually surprised by an event printed in the source code years ahead of time. The same logic shows up wherever traders position around scheduled events, from a rate decision to a token unlock; venues that let people trade the expectation tend to blunt the event itself.

Defenders answer that adoption is a slow diffusion process, that new buyers arrive on their own schedule, and that markets are not perfectly efficient. All of that is fair. But it also concedes the point that matters: if the driver of price is who is arriving and how fast, then demand, not the supply ratio, is doing the real work.

What Stock-to-Flow Leaves Out: Demand, ETFs, and the SEC

The clearest evidence that demand runs the show is the last two years. Bitcoin’s supply schedule has done nothing surprising since 2024; the flow was cut on schedule that April and has ticked down predictably since. Yet the price has swung from the low $60,000s to a record above $125,000 and part of the way back. If scarcity were steering, the ride would have been far smoother.

What actually moved the market was demand, and specifically a change in who was allowed to buy. In January 2024 the SEC approved the first US spot Bitcoin exchange-traded funds, opening a regulated on-ramp for pensions, advisors, and ordinary brokerage accounts, part of the same institutional wave now pulling Wall Street into on-chain credit. Flows into those funds, not the halving, drove the run to the 2025 record, a demand story that CoinGecko and most trading desks place at the center of the rally. When the flows cooled through 2026, so did the price, all while the stock-to-flow ratio kept ticking higher in the background.

None of this fits inside the model. A stock-to-flow chart cannot see an ETF launch, a friendlier SEC, a shift in Federal Reserve policy, or a wave of corporate treasuries adding coins to their balance sheets. It cannot see the opposite either, the deleveraging and forced selling that turns a drawdown into a rout. The forces that set Bitcoin’s price in 2026 live almost entirely on the demand side of the ledger, exactly the side the model leaves blank.

PlanB’s Defense, and What the Model Got Right

PlanB has never accepted that the model is dead. His standing defense is that the gaps between forecast and price come from outside shocks, exchange blowups, rate hikes, black-swan liquidations, rather than from any flaw in the scarcity relationship. Give it a full four-year cycle, he argues, and the average will pull back toward the line. Critics find that unfalsifiable, because any miss can be blamed on an external event and any hit credited to the model.

Still, a fair critique has to grant what S2F got right, because writing it off entirely misreads why so many sharp people believed it. Three things stand out. First, it took Bitcoin’s defining feature, programmed scarcity, and made it legible to people who think in charts. Second, it correctly insisted that halvings matter, that cutting new supply in half is not a non-event. Third, for one full cycle it was directionally right; anyone who bought Bitcoin in 2019 because a stock-to-flow chart told them scarcity was about to bite did very well, at least until 2022.

The trouble is not that scarcity is irrelevant. It is that scarcity is one input among many, and the model dressed a single input up as a complete theory. A framework that nails the direction of one bull market and then misses the next two cycles by hundreds of thousands of dollars is not a law of nature. It is a story that rhymed with the data for a while.

The Alternatives: Power Law, Rainbow, and On-Chain

S2F’s stumble left a vacuum, and other quantitative models moved to fill it. The most cited successor is the Bitcoin power law, developed by the physicist Giovanni Santostasi, which drops scarcity entirely and models price as a function of time raised to an exponent near 5.8. Santostasi stitches together three separate power laws, one for address growth, one for price versus users, and one for hashrate, to argue that Bitcoin behaves less like a stock with a catalyst schedule and more like a city or a network that grows on a predictable long-run curve. Its backers note that it has held up better than S2F through the 2024 halving and the swings since.

Then there is the rainbow chart, a color-banded logarithmic regression that maps sentiment zones from fire sale to bubble. It is less a forecast than a mood ring, but it has stayed loosely in touch with price where S2F ran away from it. And a whole family of on-chain indicators, from realized price to the difficulty-based signals traders use to time cycles, try to read demand and miner behavior directly instead of assuming supply alone sets value. Our own look at Bitcoin’s difficulty ribbon ran into the same lesson these models keep teaching: an indicator that worked beautifully in past cycles can quietly stop working when the market’s structure changes.

None of these is a crystal ball, and the power law carries its own version of the spurious-time-trend objection. But most of them at least try to account for the demand side, which is the entire dimension S2F leaves empty.

S2F in 2026: A $500,000 Model Meets a $64,000 Market

So where does the model stand today? On paper, gloriously bullish. With Bitcoin’s stock-to-flow ratio above 100 after the 2024 halving, the regression now points to a cycle average near $500,000, and some readings of the curve imply seven figures before 2028. By some measures, the gap between the model’s fitted line and the actual price has blown out past $100,000, with the chart calling for several times what Bitcoin fetches in the market.

The reality is a coin trading in the mid $60,000s in August 2026, down 43% on the year and well off its 2025 high. That combination, an ever-more-bullish model diverging ever further from an ever-more-sideways price, is exactly the failure mode critics warned about back in 2020. The model cannot lose, in the sense that it can always claim vindication is one bull run away. But a forecast that is forever about to be right is doing something other than forecasting.

Precision matters here. Bitcoin has not collapsed; it is still one of the best-performing assets of the past decade, with a market value around $1.33 trillion. What has failed is the specific claim that a single supply ratio can tell you what that value will be. Scarcity did not stop mattering. It just never mattered in the tidy, mechanical way one chart promised.

How to Read a Bitcoin Price Model Without Getting Burned

The S2F saga leaves a handful of durable lessons for anyone weighing the next confident price target, and they travel well beyond Bitcoin.

• Beware two lines that both go up. A high R-squared between rising time series is the easiest illusion in quantitative finance. Ask whether the relationship survives a proper cointegration or stationarity test before you trust it.
• Watch for moving goalposts. A model that quietly separates its floor from its core, or recasts a failed target as a timing issue, has stopped making falsifiable claims.
• Demand is not a footnote. Any model that ignores who is buying and why, ETFs, regulation, rates, adoption, is describing at most half of the machine.
• Public schedules get priced in. If a catalyst is known years ahead, the market has years to front-run it. Certainty about supply does not translate into certainty about price.
• One good cycle is not proof. Being directionally right through a single bull market is what you would expect from a broadly bullish view in a broadly rising asset. The real test is the cycle that does not cooperate.

None of that means ignore scarcity, or that Bitcoin can never reach the numbers S2F dreams of. It means treating any single-variable model of a global, reflexive, demand-driven market as a lens, not a law. PlanB built the most influential chart in crypto history. Its lasting lesson, in the end, is how much a beautiful fit can hide.

Frequently Asked Questions

What is the Bitcoin Stock-to-Flow model in simple terms?

It is a valuation model created by the anonymous analyst PlanB in 2019 that estimates Bitcoin’s price from its scarcity. It divides the existing supply, called stock, by annual new issuance, called flow, and maps that ratio, the same one used for gold and silver, onto a market value. Because Bitcoin’s issuance is cut in half about every four years, the model’s projected price steps up sharply after each halving.

Did the Stock-to-Flow model fail?

By its own tests, yes. PlanB’s floor model missed its November and December 2021 targets of $98,000 and $135,000, and Bitcoin fell through the model’s lower band in June 2022 on the way to about $15,500 that November. PlanB has conceded that the floor model failed while arguing the core regression is intact, a distinction most independent analysts reject.

What does Stock-to-Flow predict for Bitcoin now?

After the April 2024 halving lifted Bitcoin’s stock-to-flow ratio above 100, the model points to a 2024 to 2028 cycle average near $500,000, and some readings imply even more. As of August 2026 Bitcoin trades around $64,000, so the gap between the model and the market is very wide.

Why do critics say the model is statistically flawed?

The main objection is spurious correlation. Both Bitcoin’s stock-to-flow ratio and its price rise over time, so regressing one on the other produces a high R-squared even without a real causal link. Analysts including Alex Kruger and Nick Emblow argue there is no genuine cointegration between scarcity and price, which means the ratio cannot reliably predict value.

Is there a better model for Bitcoin’s price?

There is no proven crystal ball, but several frameworks have aged better than Stock-to-Flow, including Giovanni Santostasi’s power law, which models price against time and network growth, and demand-aware on-chain indicators. Their shared advantage is that they try to account for adoption and demand, the forces that drove Bitcoin’s ETF-fueled 2025 rally and its 2026 pullback, rather than supply alone.

By the HOGE Wire markets desk. We cover crypto, macro, and the models traders actually use. Nothing here is investment advice.