Spot bitcoin exchange-traded funds (ETFs) in the U.S. experienced their 13th consecutive day of net inflows on Thursday, amassing $48.71 million. Notably, significant fund movements were observed in two bitcoin funds offered by Fidelity and Ark Invest, as reported by SoSoValue data.

Fidelity’s FBTC led the charge with net inflows totaling $119 million, while Ark’s ARKB faced substantial net outflows, nearing $100 million. ARKB's outflow on Thursday marked its largest since its launch in January.

BlackRock’s IBIT, the largest spot bitcoin fund by net assets, observed net inflows of $2 million. In contrast, Grayscale’s GBTC reported zero flows. Bitwise’s BITB received $26 million in funds, while Invesco and Galaxy Digital’s bitcoin ETF noted $2 million in net inflows.

According to Rachael Lucas, Crypto Analyst at BTC Markets, these unusual flows in spot bitcoin ETFs seem to reflect investor uncertainty regarding the Federal Reserve's interest rate trajectory, particularly ahead of major economic reports scheduled for release from the U.S. on May 31. Lucas explained that if U.S. inflation numbers surpass expectations and trends in personal income and spending rise, it could dampen investor optimism about a potential Fed rate cut in September. A more hawkish Fed stance could negatively impact demand for riskier assets like bitcoin and related ETFs.

Over the past 13 days, U.S. spot bitcoin ETFs have witnessed total net inflows exceeding $2 billion, marking their second-longest positive streak since listing, second only to the 17 consecutive days of net inflows starting in January. However, despite this positive streak, the total volume of flows in U.S. spot bitcoin ETFs remains notably smaller than their peak in March.

In parallel news, Grayscale filed its amended S-1 registration statement for its spot Ethereum fund on Thursday, following BlackRock’s filing a day earlier. With the SEC urging issuers to submit their forms by Friday, further S-1 filings are anticipated to follow suit.