BlackRock’s iShares Bitcoin Trust lost $527.84 million on Wednesday, the second-largest single-day net outflow since the fund launched in January 2024, according to data from SoSoValue.
The figure missed the record by a very narrow margin. The largest IBIT outflow on record remains the $528.3 million withdrawn on January 30, which Wednesday’s withdrawal was about $500,000 short of matching. The fund holds approximately $59 billion in assets and represents about 4% of the total bitcoin supply, making it the largest single vehicle of institutional exposure to bitcoin.
The departure was part of a broader exodus. The 11 US-listed spot bitcoin ETFs lost a combined $733.43 million on Wednesday, with Fidelity’s FBTC losing $60.30 million and Grayscale’s GBTC losing $104.76 million along with the IBIT draw. The complex has seen capital outflows for several consecutive sessions, with more than $2 billion withdrawn in the last two weeks.
The sale occurred on the same day that Bitcoin broke below $73,000. The cryptocurrency was trading at $72,978 in Asian time on Thursday, down 3.4% in 24 hours, after US airstrikes on an Iranian military site near the Strait of Hormuz reignited a conflict that markets had begun to discount. The ETF outflows and the price decline fueled each other, and the redemptions forced BlackRock and other issuers to sell the underlying bitcoin to settle investor outflows.
The IBIT withdrawal came a day after another eye-catching move in the fund. On Tuesday, a single investor sold $1.29 billion worth of IBIT shares in a dark pool block trade, as CoinDesk reported.
A dark pool trade is a privately negotiated transaction that allows big players to change size without alerting the broader market.
That block sale was not the same as a net outflow, as buyers can step in to absorb the volume, and actual net IBIT redemptions on Tuesday amounted to $192.44 million. But the two events together point to institutional players cutting exposure to bitcoin as the macro context changed.
Flow data has been pointing in this direction for weeks. ETF accumulation over the year had already narrowed to a net of around 4,500 BTC, and May moved from constant March and April buying to distribution, as reported on Wednesday. Bitcoin has fallen from over $82,000 on May 6 to below $73,000 now, and the channel ETF that fueled the 2025 rally has spent the month throwing money the other way.
Whether the exits reflect a tactical de-risking amid Hormuz headlines or a deeper institutional retreat depends on what happens once the situation in the Middle East stabilizes. IBIT has already gone through prolonged spells of outflows during this cycle without a permanent reversal, and money returned every time the macroeconomic picture became clearer.
