U.S. spot Bitcoin and Ethereum ETFs experienced notable fluctuations in net flows during the first week of August 2025. From July 28 to August 1, Bitcoin ETFs recorded $643 million in outflows, ending a seven-week inflow streak, while Ethereum ETFs gained $154 million, driven mainly by BlackRock's ETHA product. However, on August 4, both Bitcoin and Ethereum ETFs faced substantial outflows, with Bitcoin ETFs seeing $696 million in withdrawals and Ethereum ETFs experiencing their largest single-day net outflows of $465.1 million, primarily due to BlackRock's ETHA, which accounted for $375 million of the outflows. The trend of outflows continued on August 5, with Bitcoin ETFs losing $440.35 million and Ethereum ETFs dropping $565.93 million, again led by BlackRock's significant withdrawals. Despite these declines, August 6 saw a reversal with Bitcoin ETFs posting a $91.55 million net inflow and Ethereum ETFs gaining $35.12 million. On August 7, inflows accelerated, with Bitcoin ETFs adding $277.4 million and Ethereum ETFs $222.3 million, largely driven by BlackRock's IBIT and ETHA products, which contributed $156.6 million and $103.5 million respectively. The data highlights BlackRock as a key player influencing ETF flows during this period, with other providers such as Fidelity, Grayscale, Ark, and VanEck also contributing to daily flow variations. Overall, the week was marked by a sharp midweek downturn followed by a strong recovery in both Bitcoin and Ethereum ETF investments.