US spot Bitcoin ETFs pulled in $3.52 billion in August, the strongest month of the year, before BlackRock's IBIT drove the bulk of a sharp single-day reversal on September 1.
US spot Bitcoin ETFs closed August with $3.52 billion in net inflows, the strongest month of 2026, according to SoSoValue data. That strength reversed on September 1, with $236.46 million in net outflows in a single day, of which BlackRock's IBIT accounted for roughly 85%. The figures haven't been independently verified against a second flow tracker.
Bitcoin's own price has been roughly flat to slightly higher over the same period, which argues against the outflow representing a broad flight from the asset and toward a more contained explanation, such as a single large holder rebalancing through IBIT specifically. Whether that rebalancing is a one-off or the leading edge of a broader institutional pullback, and whether outflows stay concentrated in IBIT or spread across issuers in the coming weeks, is the open question.