US Spot Bitcoin ETFs Pull In $987M for the Week; Three-Week Inflow Run Reaches $3.8B

US spot Bitcoin exchange-traded funds recorded $986.9 million in net inflows for the week ended September 5, extending a three-week buying streak that has brought total inflows to $3.8 billion. Despite the recent surge, flows remain in the red for the year. After a difficult start to 2026, year-to-date net inflows are still around negative $1 billion, though the latest three-week run has sharply reduced the shortfall. Inflow activity was heavily concentrated on Thursday, which drew roughly $731 million in net new money, the largest single-day intake since January 14. Friday slowed to $174.6 million, led by BlackRock's iShares Bitcoin Trust (IBIT) with $117.4 million and Fidelity's Wise Origin Bitcoin Fund (FBTC) with $57.2 million. Total assets under management across all US spot Bitcoin ETFs stood at $101.3 billion at the latest reading, after briefly reaching $103.3 billion during the week. Since their January 2024 debut, the group has accumulated $55.6 billion in cumulative net inflows. Bitcoin traded largely steady over the week, hovering near $80,000. The price briefly dipped below $79,000 before rebounding to about $79,700. Other crypto ETF categories showed weaker momentum. Spot Ether ETF inflows fell 74% week over week, and XRP ETF products posted an 83% decline. August 2026 brought $3.5 billion in total Bitcoin ETF inflows, the strongest monthly haul since September 2025. The fact that year-to-date flows remain near negative $1 billion even after $3.8 billion of inflows over three weeks underscores the scale of the earlier outflows. At around $80,000 per bitcoin, Bitcoin's fully diluted market capitalization is roughly $1.6 trillion. With $101.3 billion in combined AUM, US spot Bitcoin ETFs account for a meaningful share of the market, holding about 6% of all bitcoin that will ever exist.