Bitcoin ETF Buyers Showed Up the Week the Fed Hiked
U.S. spot bitcoin funds took in about $2.06 billion in three sessions, their strongest run since October 2025, just as the Fed raised rates and the 10-year yield passed 5.1%.
On Monday, September 21, U.S. spot bitcoin ETFs took in $998.95 million in a single session, according to SoSoValue data reported by The Block. That was the largest daily inflow in 11 months, second only to the $1.2 billion on October 6, 2025. Tuesday added roughly $715 million. Wednesday added $346.98 million.
Together that is about $2.06 billion in three trading days, the strongest run of buying since October 2025. Counting the inflows on September 17 and 18, the streak reached five sessions and $2.65 billion.
The flows alone are notable. The timing is more so. This money came in the week after the Federal Reserve raised rates for the first time in more than three years, while the 10-year Treasury yield climbed to 5.116%, its highest since July 2007. By the usual logic, a non-yielding asset should lose buyers in that setting. This week it gained them.
Who was buying
The leaders on Monday were BlackRock's IBIT at $381.4 million, ARK and 21Shares' ARKB at $289.1 million, and Fidelity's FBTC at $238.8 million. Grayscale, Bitwise and Morgan Stanley's funds also took in money. On Wednesday, IBIT added $166.29 million, FBTC $143.24 million, Morgan Stanley's MSBT $32.41 million and ARKB $5.04 million, according to figures compiled by Trader T and reported by TechFlow.
The spread matters. When one fund dominates a flow spike, it often reflects a single large allocator or a basis trade being put on. When ARKB takes in almost as much as IBIT in one day and a new entrant like MSBT shows up on the list, demand is coming from more places. That is an inference from the fund-level data, not a disclosed fact about who bought.
Spot ether ETFs moved too, adding $269.98 million on Monday, their best day since October 7, 2025.
The price did not keep up with the flows
Bitcoin reached about $87,300 on Monday, its highest level since January, per The Block. By Wednesday it had slipped to about $84,650, down 1.7% on the day, according to Investing.com. Heavy ETF buying and a lower price in the same week is worth noting.
Part of the explanation is that Monday was not only ETF demand. About $1.06 billion of crypto positions were liquidated in 24 hours, $844 million of them shorts. Forced short covering adds buying that disappears once the positions are closed. Min Jung of Presto Research described the move to The Block as a mix of "renewed risk appetite, strong spot ETF demand and some short covering." That is a fair description. The ETF share is the part most likely to stick, because ETF holders are not using leverage and cannot be liquidated.
Also consider the starting point. Just before the streak, the same funds lost $450.4 million on September 15 and $295.9 million on September 16, the days around the Senate's failed 49-50 cloture vote on the CLARITY Act and the Fed decision. The buying started once those two events had passed.
Why the cost basis matters
One figure explains a lot of this week's behavior. Bloomberg estimates the average ETF holder's cost basis at about $81,722 per bitcoin, and Pepperstone puts it near $82,000. Bitcoin began 2026 near $87,500 and fell into the high $50,000s at its low for the year, which left much of the ETF base with losses for months.
This week's move lifted the price back above that average cost. Holders who have been underwater tend to sell as soon as they break even. A three-day run of net inflows right at that level indicates that, for now, new buyers are absorbing whatever selling came from break-even holders. That is the case for a floor: a large group of holders now slightly in profit, with new money arriving above their cost.
The flows also changed the annual total. Per Bloomberg, Monday's session brought year-to-date spot bitcoin ETF flows back to positive, about $320 million, for the first time since April. Roughly $4.6 billion has come in since August 19, when the Treasury doubled its long-end buyback operations and bitcoin started recovering.
The risks
The macro backdrop is still unfavorable. After the September 16 hike, markets priced roughly a 68% chance of another increase in October, up from about 55% a day earlier, per Investing.com. The 10-year yield is at its highest in 19 years. If yields keep rising, a portfolio that added bitcoin this week will face the same rate pressure that bitcoin has so far ignored.
The near-term catalyst is political. Xi Jinping's state visit to the U.S. starts this week, the first such visit in over a decade. Jeff Mei, COO of the exchange BTSE, linked this week's institutional buying to falling oil prices, easing yields at the start of the week, and a meeting that could lead to breakthroughs on AI, trade and Iran. Bets placed ahead of a summit tend to reverse if it disappoints.
Bitcoin also remains below where it began the year and about a third below its October 2025 record above $126,000. A strong three-day stretch of inflows does not change that.
What to watch
Three things will show whether this was a floor or a squeeze. First, whether net inflows continue on days when the price falls, which is when committed buyers separate from momentum traders. Second, whether bitcoin stays above the roughly $82,000 average ETF cost basis, because a drop below it would push that holder base back into losses. Third, how the flows respond to the October Fed decision, since the market already expects another hike.
The ETF buyers did something unusual this week. They added bitcoin while rates rose. The next few weeks will show whether they are long-term allocators or simply followed a squeeze.