Study · re-run every night · updated Oct 15, 2026

Does Bitcoin follow the stock-to-flow model? Every close since PlanB published it

PlanB's stock-to-flow model, published on Mar 22, 2019, priced Bitcoin at $810,575 on Oct 14, 2026: it closed at $81,682, at 10% of the model's price. Since the model was published, Bitcoin closed within a factor of 2 of its price on 35% of 2,764 days and over it on 13%; the middle close sat at 32% of it. On the closes from the years it was fitted on (2014 to 2019, ours), within a factor of 2 on 65% of 1,906 days. Each halving halves the new coins, so the model's price jumps about tenfold overnight: from $78,450 to $772,750 at the Apr 20, 2024 halving. Bitcoin's highest close since: $124,659 on Oct 6, 2025, at 16% of the model's price that day. Past patterns, not financial advice.

Close over the model

0.10×

on Oct 14

Within 2× since 2019

35%

of 2,764 days

Over the model

13%

of days since it was published

The model's price

$810,575

SF 121

First written Oct 15, 2026 · 1 revision

§ 01 · Today

Today

as of Oct 15, 2026 · Bitcoin's daily closes, Jan 1, 2014 to Oct 14, 2026

"Bitcoin follows the stock-to-flow model", the saying goes. On Mar 22, 2019 the analyst PlanB published it: a coin's scarcity as its stock-to-flow, the coins already mined over a year's new ones, and Bitcoin's market value fitted to it on the monthly data up to then, ln(market value) = 3.3 ln(SF) + 14.6. Every halving cuts the new coins in half and doubles the ratio, so the model's price jumps about tenfold overnight (2 to the power 3.3). A line fitted to the past fits its past; the test is the days after it was published, none of which it saw. Here every close is set against the model's price that day.

Oct 14, 2026: Bitcoin closed at $81,682, at 10% of the model's price of $810,575 (a stock-to-flow of 121: 20,100,846 coins mined, 166,341 new ones a year). The day the model was published Bitcoin closed at $3,987, at 71% of its price of $5,633.

Bitcoin (a log scale)the stock-to-flow model's pricesince it was published

§ 02 · Before and afterMEASURED

Before and after it was published

as of Oct 15, 2026 · every close against the model's price that day

Closes	Days	Within 2× of it	Over it	Middle close	Lowest	Highest
Before it was published Jan 1, 2014 – Mar 21, 2019	1,906	65%	55%	1.16×	0.12× Aug 2, 2016	4.64× Jan 6, 2014
Since it was published Mar 22, 2019 – Oct 14, 2026	2,764	35%	13%	0.32×	0.07× Sep 6, 2024	2.27× Jun 26, 2019

Since the model was published, Bitcoin closed within a factor of 2 of its price - between half of it and twice it - on 35% of 2,764 days, and over it on 13%. The middle close sat at 32% of the model's price; the furthest under was at 7% of it on Sep 6, 2024, the furthest over at 2.27 times it on Jun 26, 2019. On our closes from the years it was fitted on, within a factor of 2 on 65% of 1,906 days.

§ 03 · Halving by halving

Halving by halving

as of Oct 15, 2026 · each era between two halvings

Era	New coins a block	The model's price	Bitcoin's highest close	Within 2×	Middle close
The 2012 halving Jan 1, 2014 – Jul 8, 2016	25	$197.17 to $362.17	$919.24 Jan 6, 2014, 4.64×	72%	1.29×
The 2016 halving Jul 9, 2016 – May 10, 2020	12.5	$4,365 to $6,222	$19,103 Dec 16, 2017, 3.81×	70%	1.16×
The 2020 halving May 11, 2020 – Apr 19, 2024	6.25	$66,946 to $78,450	$73,072 Mar 13, 2024, 0.94×	40%	0.40×
The 2024 halving Apr 20, 2024 – Oct 14, 2026	3.125	$772,750 to $810,575	$124,659 Oct 6, 2025, 0.16×	0%	0.10×

Each row is one era between halvings, from the halving's day (or our first close) to the day before the next; the multiples are a close over the model's price that day. The current era is marked, its highest close so far.

§ 04 · How it is tested

How it is tested

as of Oct 15, 2026 · methodology

The model is PlanB's of Mar 22, 2019 as published: market value = e^14.6 × SF^3.3, in dollars, and the price that market value over the coins mined. Stock-to-flow is the coins mined up to a day over a year's new coins at that day's pace. Both come here from Bitcoin's issuance schedule: 50 new coins a block at first, halved every 210,000 blocks; each finished era's 210,000 blocks spread evenly over its days (the halvings' days from our hand-checked file, the first on Nov 28, 2012), the current era's at the last finished one's pace (145.8 blocks a day). PlanB's own chart counted each month's mined coins, so its line wobbles around this one by a few percent; next to the gap between the model and Bitcoin's price that is small.

There is no luck test: it is one published line against one price, not a pattern picked out of many, so the counts are given as they are. "Within a factor of 2" is a loose bar on purpose: a model off by half or by double still counts as near. Our closes start with Bitstamp's from Jan 1, 2014 and miss Bitcoin's first five years, which the model was fitted on too. Prices are Bitcoin's own closes in dollars.

§ 05 · Revisions1 dated

Revisions

as of Oct 15, 2026 · every change to its headline numbers, dated

This study is re-run every night on the whole history: Bitcoin's daily closes from Jan 1, 2014 to Aug 16, 2017 are Bitstamp's, Europe's oldest exchange, and ours from the next day on (on the 3,346 days both have, the two closes differ by 0.06% in the middle case). It was first written on Oct 15, 2026; its numbers last moved on Oct 15, 2026. Each night its headline numbers moved is listed here, newest first.

Oct 15, 2026Since the model was published: within a factor of 2 of its price on 35% of days · the middle close 0.32 times its price · today 0.10

§ 06 · More

More research

as of Oct 15, 2026