The $63B revolving door of US Bitcoin ETF flows

BlackRock’s iShares Bitcoin Trust (IBIT) collected $63.939 billion in net inflows from January 2024 through Sept. 3, 2026, according to Farside Investors. The entire US spot Bitcoin ETF group recorded $55.512 billion in net inflows over the same period, leaving other funds with a combined net outflow of $8.427 billion.

Grayscale’s GBTC registered $27.653 billion of net outflows since January 2024 after converting to an ETF and opening a redemption path for long-held shares. Excluding both IBIT and GBTC from the category totals, the remaining spot ETFs recorded $19.226 billion in cumulative net inflows.

BlackRock reported approximately $63.44 billion in IBIT net assets as of Sept. 3, 2026, with 1.375 billion shares outstanding. The fund charges a 0.25% sponsor fee and had a 30-day median bid-ask spread of 0.02%. IBIT holds only Bitcoin and trades on Nasdaq while providing standard ETF features including conventional account statements and custody arrangements.

Across 14 trading sessions from Aug. 17 through Sept. 3, 2026, IBIT captured $2.843 billion of the group’s $3.655 billion in inflows, equal to 77.8% of the period’s net new money. Daily flow data show IBIT at times offsetting redemptions elsewhere and at other times showing outflows of its own.

On Aug. 27, IBIT reported $277.6 million of primary-market inflows while the entire US spot group showed $242.3 million in inflows, implying combined outflows of $35.3 million from other funds that day. On Sept. 1, IBIT recorded a $201.2 million outflow while the category posted a $236.5 million withdrawal. On Sept. 2, IBIT added $115.4 million as GBTC lost $56.2 million, and on Sept. 3 IBIT added $454 million while the group posted $730.8 million in net inflows.

Primary-market creations and redemptions change the ETF’s Bitcoin holdings: authorized participants create new shares in large blocks, adding Bitcoin to the trust, or redeem shares, removing Bitcoin from the trust. Secondary-market trading moves existing shares between investors without changing the trust’s Bitcoin holdings. Arbitrage activity tends to keep the ETF’s market price close to its net asset value by prompting creations when the ETF trades above NAV and redemptions when it trades below NAV.

Distribution and account structures affect where US retail and institutional flows go. Financial advisers can place IBIT in model portfolios, retirement accounts can hold it without special custody steps, and deep daily trading can make large orders easier to execute. IBIT expands only when investors request new shares and contracts when they redeem, so net creations and redemptions determine whether the trust’s claim on Bitcoin grows or shrinks.

Market participants track shares outstanding, primary-market creations and redemptions, trading volume, and any premium or discount to NAV to measure how ETF activity affects Bitcoin exposure. These metrics show whether capital entering the US spot ETF market is enlarging the trust’s Bitcoin holdings or moving between existing shareholders.