Supply and Scarcity · Published

Bitcoin Supply Shock: 5.2x at One Month, Zero at Three

How much bitcoin did ETFs buy against new supply?

Over the twenty reporting sessions from August 4 through August 31, US spot bitcoin ETFs absorbed 46,362 BTC against the 9,000 BTC the network minted across the same sessions — a ratio of 5.15x. Stretch the same calculation to sixty sessions and the answer changes sign: from June 5 through August 31 the category took -231 BTC against 27,000 BTC mined, a ratio of -0.01x. Both numbers are correct. The bitcoin supply shock currently showing up in the data is a one-month event sitting on top of a quarter in which the funds removed, on net, about half a day of issuance and then handed it back.

That gap is this week's story, and it is the thing the single headline ratio hides. The arithmetic behind it is simple: each session's net ETF flow is converted to BTC at that day's close, then divided by the 450 BTC the network mints daily. Above 1.0 the funds consumed more bitcoin than miners created; below zero, redemptions returned coins to the market. bryptoflows builds the series from Farside Investors flow data and Hyperliquid closes — the rolling chart sits on the institutional signal dashboard and the underlying flows on the ETF flow dashboard. Every figure below is computed from that dataset, current through the August 31 session, with all twelve tracked products reporting.

August absorbed 5.19x new supply, its best month in thirteen

The calendar month is now complete and it is the strongest reading in over a year. Across August's 21 reporting sessions, $3,539M of net flow converted to 49,041 BTC against 9,450 BTC of issuance — 5.19x. In the 32 months since spot ETFs launched, only four have been stronger: February 2024, October and November 2024, and July 2025. None of the thirteen months since July 2025 beat it.

Set against the rest of this year, August is a reversal rather than a continuation:

The rolling 20-session reading tracks that turn tightly. It stood at 4.22x when last Tuesday's absorption piece was written and has climbed through 4.76, 5.03, 4.96, 5.14 to 5.15x — a slow grind rather than one outsized session. It now sits above 98.8% of the 166 rolling readings recorded in 2026 and above 79.6% of all 658 readings since January 2024. The last time the window printed this high was May 6, at 5.25x.

Five of the last twenty sessions were still negative, including August 28, when -$201.9M released 2,594 BTC back to the market at -5.76x issuance. The most recent session, August 31, ran +$216.7M, or 2,758 BTC at the $78,574 close — 6.13x that day's mint.

The bitcoin supply shock has a term structure, and it inverts

Run the same absorption calculation across every horizon and the result is not one number but a curve. As of August 31:

Read from the bottom up, that curve says the ETF complex spent the spring returning coins, spent July roughly break-even, and spent August taking them off aggressively. Read from the top down, it says the aggression is already fading at the short end: the trailing five sessions are running at 4.50x, well under the trailing ten at 8.23x. The peak intensity of this episode was the week of August 17 to 21, not last week.

The forty-session figure is the honest middle. At 2.68x it is comfortably above 1.0 — genuine bitcoin supply absorption over two months — while being roughly half the one-month reading. Anyone quoting the 20-session number as the state of ETF demand is quoting the most flattering window available.

Why $598M of net inflows removed zero bitcoin

The sixty-session result deserves an explanation, because on the surface it contradicts the dollar data. Measured in dollars, the trailing sixty sessions are positive: +$598M of net flow. Measured in coins, the same sixty sessions are negative: -231 BTC. A positive dollar number produced a negative coin number, and the reason is entirely execution price.

Split the window by direction:

Redemptions cleared at prices roughly 11.2% below where creations cleared. That is enough for the smaller pile of dollars leaving to carry more coins than the larger pile arriving. The complex sold cheap in June and bought back dear in August, and the 231-coin deficit is the residue.

This is the specific reason a coin-denominated absorption series is worth computing separately from a dollar-denominated flow series, and it is where this article and Monday's flow analysis diverge on the same underlying data. Monday's finding — that the trailing 60-session net flow crossed above zero for the first time since May — is accurate in dollars. In coins, that same window has not crossed zero. Had every one of those dollars executed at the August 31 close instead of at the prices actually available, the sixty-session figure would read +7,617 BTC rather than -231. The rally that made the dollar number look like a recovery is the same rally that stopped it from being one in coin terms.

One caveat before reading that as allocator incompetence: the coin deficit measures what the market absorbed, not the timing skill of any fund.

What has to arrive for the ratio to hold

Because it is a trailing window, the 20-session ratio decays without new demand. The arithmetic is fully determined and worth stating in advance rather than after the fact.

The five oldest sessions in the current window — August 4 through August 10 — carry +8,529 BTC between them. They roll out over the next five reporting sessions. If net flow from here is exactly zero, the rolling reading falls from 5.15x to 4.20x on its own. To hold 5.15x, the next five sessions must deliver roughly 8,530 BTC, which at the August 31 close is about $670M of net inflow in a week — a pace the category has hit only in its strongest stretches. Ten sessions of zero flow drags it to 4.11x.

Falling below 1.0x is a much more distant proposition: it would take net redemptions of roughly 28,800 BTC over five sessions, which nothing in the 2026 record approaches. The number to watch is not whether absorption stays positive; it is whether the sixty-session figure — currently at zero — can climb into positive territory as June's redemptions age out of it. That is the reading that would mark a durable change in bitcoin scarcity from this channel rather than a good month.

Bitcoin daily issuance is 450 BTC, and the halving sets the next step down

The denominator is the only stable part of this calculation. Bitcoin daily issuance is 450 BTC — a 3.125 BTC block subsidy across roughly 144 blocks a day — and it stays there until the next halving cuts it to 225. It does not respond to price, to hashrate leaving for AI data-center contracts, or to difficulty retargets, which exist precisely to hold issuance at target no matter how much computing power is attached. That is what makes ETF demand versus bitcoin mined a meaningful comparison at all: one side is a market variable, the other is a protocol constant.

Against that constant, the cumulative figure is the durable version of the bitcoin scarcity argument. Since January 2024, net ETF creations converted at each day's close total 653,576 BTC. At 450 a day that is 1,452 days of production — just under four years of issuance held by a product category thirty-two months old, and a little over 3% of every bitcoin mined to date. Across the full 677-session history, absorbed against issued, the ratio is 1.94x: the ETF complex has consumed a shade under two coins for every one the network created since it opened.

That life-to-date number is the one least sensitive to which window you happen to be standing in, and it has barely moved this year. 2026 to date runs -31,822 BTC against 74,700 issued, or -0.43x, against 1.53x for 2025 and 3.46x for 2024 — a demand channel that decayed for two years, went negative this year, and has spent one month looking like its old self.

What the absorption ratio does not count

The metric is narrow by construction, and the narrowness matters more this week than usual because the sixty-session zero invites over-reading.

And the ratio is a demand proxy, not a price forecast. It is measured in coins but arrives in dollars, which means a rising price mechanically lowers it — the more successfully this channel bids the market up, the fewer coins each subsequent dollar removes. Bitcoin closed the window's first session at $64,068 and its last at $78,574, up 22.6%. Extrapolating a high absorption ratio into a price path argues against the metric's own arithmetic.

Strategy stopped absorbing while the ETFs restarted

Corporate treasuries are the second channel that removes coins faster than miners create them, and the two channels moved in opposite directions in August. Strategy's SEC filings, current through August 24 on bryptoflows' dataset, show holdings of 840,447 BTC — up from 673,783 BTC in its first 2026 filing, roughly 166,700 BTC added against about 106,200 BTC of issuance over the same span, or 1.57x.

The recent direction has reversed, though. Its last filing reporting an acquisition was June 22, at +520 BTC. Of the nine filings since, three were sales — -3,588 BTC on July 6, -1,638 BTC on August 3 and -1,690 BTC on August 10 — and six reported no change. While the ETF complex absorbed 49,041 BTC in August, the largest corporate holder sold 3,328 and bought nothing. Thursday's treasury piece owns that thread in detail; the point here is that August's absorption was an ETF story rather than a broad institutional one. The August monthly review covers the wider month.

The clean summary is this. One month of data says demand is taking coins off the market at five times the rate they are created. Three months of data says this channel has removed nothing at all. The reconciliation is that August undid June, roughly, at a worse price — and a supply shock that has to first undo its own prior redemptions is a genuinely different thing from one that starts from flat.