Bitcoin ETFs took 92% of September's $2.6 billion inflow in a single week

Roughly 92% of September's spot bitcoin ETF money arrived in one week: about $2.39 billion of the month's roughly $2.6 billion came in the week ended Sept. 25 ^[2][12]. The rest of the month brought in about $210 million ^[13]. Within that week, the Sept. 21 session alone took nearly $999 million, about 42% of the week's total ^[3][17]. CoinDesk attributes the September surge to large spot ETF inflows ^[20]. If that is right, the bid bitcoin needs back to clear $87,000 is the one that carried September, or rather the one that carried a single week of it ^[1].

Since then the funds have drawn $241 million last week and $28 million so far this week ^[4][5]. "I read the current move as evidence that the ETF bid that carried September has not yet returned strongly enough to offset renewed macro pressure," Oliver Carding, head of marketing at Tesseract Group, said in an email ^[6]. He set a bar: "ETF inflows above roughly $300 million a session for several sessions (my threshold rather than a market one) would be an important signal that institutional demand is returning" ^[7]. One session at that level would beat all of last week, and this week's tally is under a tenth of one ^[14]. The Sept. 21 peak was 3.3 times his threshold ^[16].

Martin Lee, head of content and data insights at DWF Labs, gives big single-day inflows more weight than long runs of inflow days that sum to only a few hundred million dollars ^[18]. "Looking across the year, we've had 93 out of 190 (48%) trading days be negative while still seeing net $1.2B of inflows. Longer-term (week/month) size of flows is more important compared to daily, which is almost a coin flip this year," he said ^[19]. If his $1.2 billion and the $2.6 billion September figure cover the same funds, the rest of the year netted outflows of about $1.4 billion, and September was the year's exception ^[21]. The two figures come from different speakers and may not draw on the same data.

The ETF explanation has two rivals. Macro is one. Bitcoin fell about 1.5% to just above $84,200 in Asian trading on Wednesday as oil climbed on Iranian attacks on tankers in the Strait of Hormuz, lifting Treasury yields and the dollar ^[8]. Investors are also waiting on Federal Reserve minutes for signals on a possible rate hike, according to Reuters ^[9]. Buyers outside the ETFs are the other. "Investors appear to be using periods of weakness to accumulate and dollar-cost average alongside institutional buyers," said Paul Howard, senior director at Wincent ^[10].

Supply is moving too. Wallets linked to the US government sent 833.599 BTC, worth about $71.6 million, to two addresses that Arkham does not label, and CoinDesk reported that no sale has been confirmed ^[11]. If sold, those coins would be worth about 2.6 times this week's ETF intake ^[15].

I think the evidence supports a narrow version of the ETF thesis. September's move came with one heavy ETF week, and nothing since has come close ^[12][5]. The material does not show whether the flows drove the price or followed it. Two outcomes would cut against the thesis: bitcoin closing above $87,000 on sessions well short of $300 million, or several $300 million sessions that leave it under the range while yields climb ^[7].