The iShares Bitcoin Trust (IBIT) from BlackRock crossed $91 billion in assets under management on 2 October 2025, placing it among the top 20 ETFs by assets. The fund took in $405.5 million that day, its largest single-day deposit since 14 August 2025, channeling institutional cash and touching custodians, investors and Bitcoin derivatives.
IBIT crossed $91 billion in AUM on 2 October 2025 and recorded $405.5 million in daily inflows, the biggest since 14 August 2025, marking a notable resurgence of institutional activity. These moves underscore IBIT’s expanding footprint across spot exposure and derivatives, while highlighting dynamics in flows that can shift quickly and affect liquidity and risk management.
Data show $61.37 billion of net inflows since launch and 745,000 BTC held on 30 September 2025, reflecting sustained demand and significant on-chain footprint attributed to the fund.
Details of Blackrock ETFs
The fund passed $80 billion in July 2025 and held more than half of all spot-Bitcoin-ETF assets in April 2025, indicating IBIT’s outsized role in the spot-ETF segment. BlackRock’s ETF complex is on track to earn about $260 million in annual fees, while late September 2025 brought several days of outflows, a reminder that flows can reverse quickly.
IBIT now lists more open interest in Bitcoin options than Deribit, suggesting the ETF’s growing relevance as a venue for derivatives exposure.
Institutional demand and Bitcoin supply are increasingly intertwined as a lock-up of 745,000 BTC reduces float, allowing small changes in flows to influence price more readily.
Concentration and market risk emerge as a single issuer controls over half of spot-BTC-ETF liquidity, which can aid tracking but raises redemption risk if many investors exit at once.
Derivatives evolution is evident as IBIT’s top rank in options open interest signals that ETFs now function as hubs for complex institutional trades, beyond passive buy-and-hold roles.
IBIT reached $91 billion in AUM in early October 2025 and saw its largest daily inflow since 14 August. In the short term, institutional participants and compliance teams will need to monitor daily flows and options open interest to evaluate impacts on liquidity, concentration and operational risks.
