U.S. spot Bitcoin ETFs recorded $450.4 million in net outflows on Tuesday, September 15. The funds had attracted $159.9 million in the previous trading session. That marked a $610.3 million swing in daily flows.
The figures, published on September 16, cover the most recent completed trading session. Farside Investors has not yet reported results for the September 16 session.
Fidelity’s FBTC accounted for the largest share of the outflows, losing $214.8 million. BlackRock’s IBIT followed with $161.7 million in outflows. Together, the two funds lost $376.5 million, or about 84% of the day’s net outflows.
Five Bitcoin ETFs Recorded Outflows
According to Farside, Grayscale’s GBTC recorded $44.1 million in net outflows. Another $17.4 million left Ark and 21Shares’ ARKB, while Bitwise’s BITB lost $12.4 million. The other seven funds in the dataset ended the day with zero net flows.
Monday’s figures told a different story. BlackRock’s IBIT attracted $134.3 million, and Fidelity’s FBTC took in $53.3 million. Spot Bitcoin ETFs finished that session with net inflows despite a $42 million outflow from ARKB. On Tuesday, flows at both IBIT and FBTC reversed, pulling the overall total into negative territory.
Recent data shows how sharply ETF flows have shifted. The funds recorded net outflows on each of the four trading days from September 8 through September 11. Monday’s $159.9 million inflow ended that streak, but Tuesday’s $450.4 million outflow more than erased it.
ETF flow figures show the daily net amount of money entering or leaving the funds. On their own, they do not reveal every investor’s Bitcoin position or explain why Bitcoin’s price moves. They do, however, offer a measure of demand for Bitcoin exposure through U.S. exchange-traded funds.
New Flow Data in Focus Ahead of Fed Decision
The reversal came as markets awaited the Federal Reserve’s interest rate decision. According to the Fed’s calendar, its monetary policy meeting runs from September 15 to September 16. Investors will also watch the economic projections released alongside the decision.
The completed September 16 ETF data will offer a clearer indication of whether demand recovered after Tuesday’s outflows. Figures reported before the U.S. session ends should not be treated as final daily net flows.



