On Thursday, the United States witnessed a mix of inflows and outflows in Bitcoin exchange-traded funds (ETFs), resulting in a 13th consecutive day of net inflows totaling $48.71 million. However, one particular fund stood out with a record-breaking outflow.

Ark Invest's ARKB, a prominent Bitcoin ETF, experienced a significant outflow of $100 million, its largest single-day outflow since January. This record-breaking outflow from Ark Invest's fund contributed to the overall mixed flows observed in the US spot Bitcoin ETF market.

Other notable movements in spot Bitcoin ETFs included Fidelity's FBTC, which led the pack with net inflows of $119 million. BlackRock's IBIT, the largest spot Bitcoin ETF by net assets, reported modest net inflows of $2 million. Grayscale's GBTC saw no movement in net flows, while Bitwise's BITB added $26 million. Invesco and Galaxy Digital's Bitcoin ETF recorded net inflows of $2 million.

Investor uncertainty regarding the Federal Reserve's interest rate path and upcoming economic reports appear to be driving the unusual spot Bitcoin ETF flows. According to Rachael Lucas, Crypto Analyst at BTC Markets, if US inflation figures exceed expectations and personal income and spending trends rise, it could dampen investor optimism about a potential Fed rate cut in September. A more hawkish Fed could negatively impact demand for riskier assets, including Bitcoin and related ETFs.

Despite the mixed flows, US spot Bitcoin ETFs have attracted total net inflows in excess of $2 billion over the past 13 days, recording the second-longest positive streak since their inception. This suggests that while short-term fluctuations are inevitable, investor interest in Bitcoin ETFs remains strong overall.