BlackRock's IBIT Captures 91% of All Bitcoin ETF Flows in Strongest Week Since January

BlackRock's iShares Bitcoin Trust has recorded its strongest week of institutional demand since January, pulling in roughly $994 million in net inflows in the five trading days ending April 17, according to data from Farside Investors. The figure placed IBIT ninth among all US-listed ETFs by weekly inflows, putting it alongside products tracking the S&P 500 such as Vanguard's VOO and State Street's SPY.

The week's flows were notably concentrated. Bitcoin ETFs collectively attracted $996 million across all 12 spot products, and IBIT alone accounted for around 91% of that total. Fidelity's FBTC and ARK 21Shares' ARKB contributed modest additional inflows, while Grayscale's GBTC continued to see outflows as investors migrate away from its higher fee structure toward lower-cost alternatives.

Bitcoin ETFs Log Eight Straight Days of Inflows Into Late April

The strong week was not an isolated event. Through April 23, US spot Bitcoin ETFs had recorded eight consecutive days of positive flows, with the month's total reaching $2.43 billion, nearly double the $1.32 billion logged across the entirety of March. That sustained run has pushed cumulative net inflows since the ETFs launched in January 2024 to $58.55 billion, with total ETF holdings now at their highest level since November 2025.

The following week, ending April 24, saw the pace ease somewhat. Total Bitcoin ETF inflows came to $823 million for the five days, with IBIT contributing $732.6 million of that figure, supported by smaller additions from Fidelity's FBTC and ARK's ARKB. Even at that reduced rate, the trend represents a meaningful shift from the outflow-dominated environment that characterised much of the first quarter of 2026.

ETFs Absorbed Roughly Nine Times the Weekly Bitcoin Mining Output

To put the scale of the April 13-17 flows in context, the 12 Bitcoin ETFs collectively absorbed around 25,000 BTC over those five trading days, approximately nine times what miners produced in the same window at the current rate of 450 BTC per day following last year's halving. That supply and demand imbalance is one of the structural arguments Bitcoin ETF bulls have made since the products launched in January 2024: institutional vehicles are accumulating supply at a rate that mining output cannot match.

CryptoQuant noted the significance of the buying activity in a QuickTake post, observing that the last time ETF firms posted accumulation figures close to this level was in April 2025, when they added 23,900 BTC in a comparable window. The analytics firm stopped short of calling the move a structural inflection point, but the framing was notable given that the first quarter of 2026 had been defined largely by outflows and price weakness tied to geopolitical uncertainty in the Middle East.

IBIT Now Ranks Among the Top 1% of All US ETF Launches

The recent inflow figures add further distance between IBIT and its competitors in the Bitcoin ETF space. Since launching in January 2024, the fund has consistently attracted more capital than any rival product, and its growing lead reflects both BlackRock's institutional distribution network and the broader trend of advisers and pension allocators choosing established asset managers when making first-time crypto allocations. Bloomberg ETF analyst Eric Balchunas has previously described IBIT's trajectory as placing it in the top 1% of all ETF launches in US history when measured by first-year flows.

For a deeper look at how these products are structured and what to consider before buying, our guide to crypto ETFs in 2026 covers the key differences between spot and futures products, fee structures, and what the competitive landscape looks like now that institutional adoption is firmly underway.