BlackRock’s IBIT Bitcoin ETF Draws $665 Million in Largest Daily Inflow Since October 2025

• BlackRock’s IBIT logged $665.16 million in net inflows on October 19, its largest daily haul since Oct. 7, 2025.
• U.S. spot Bitcoin ETFs saw net inflows of $526.6 million, offset by outflows from Fidelity and Grayscale.
• BlackRock filed for the iShares Bitcoin Managed Protection ETF (PBIT), offering capped upside and roughly 10% downside protection via options on IBIT.

BlackRock’s iShares Bitcoin Trust (IBIT) recorded its largest daily net inflow in the past year, pulling in $665.16 million on Monday, October 19, according to data from SoSoValue. The figure marks the biggest single-day inflow since October 7, 2025, and underscores continued institutional demand for bitcoin exposure even as the asset traded in a tight range around $82,000 amid rate-hike concerns.

Driven almost entirely by IBIT, U.S. spot bitcoin ETFs as a group posted net inflows of $526.6 million for the day—the largest in nearly a month—despite outflows of $83.6 million from Fidelity’s FBTC and $54.9 million from Grayscale’s GBTC, The Block reported. Spot ether ETFs, by contrast, saw $103.3 million in net outflows, extending their negative streak to four days. Total bitcoin ETF assets stood at roughly $105.5 billion, or about 6.4% of bitcoin’s market capitalization, with cumulative net inflows since launch near $57.4 billion.

The strong IBIT flows arrived the same day BlackRock filed with the Securities and Exchange Commission for a new product: the iShares Bitcoin Managed Protection ETF, proposed to trade under the ticker PBIT. In the preliminary prospectus, the firm stated that the fund “seeks to provide upside exposure to the iShares Bitcoin Trust ETF (IBIT) and/or similar bitcoin exposure up to an approximate limit, while seeking to provide a level of downside protection.”

Unlike IBIT, which holds bitcoin directly, PBIT would not invest in bitcoin or bitcoin ETPs. Instead, it would use overlapping tranches of call option spreads on IBIT—typically buying calls struck near 90% of the reference price and selling higher-strike calls—to target an initial maximum loss exposure of about 10% per tranche before fees, while capping potential gains. The fund would also hold short-term fixed-income instruments to generate income that can offset option costs. Bloomberg ETF analyst James Seyffart noted on X that this would be BlackRock’s third bitcoin ETF filing and that similar buffer structures already exist from other issuers.

IBIT remains the largest spot bitcoin ETF, with net assets of approximately $66.4 billion. Min Jung, associate researcher at Presto Research, told The Block that the precise catalyst for Monday’s surge was unclear but that investors may be positioning for a potential “catch-up trade” in bitcoin. The inflows more than reversed the prior week’s roughly $229 million in net outflows from bitcoin ETFs, though October as a whole remained modestly negative heading into the session.