Demand for regulated cryptocurrency investment products has surged, with US-listed spot Bitcoin and Ethereum exchange-traded funds attracting more than $1 billion in new capital this week. Both categories of funds recorded their most substantial inflows since April, signaling a strong rebound.

Bitcoin ETFs See Strongest Inflows in Months

According to data from SoSoValue, spot Bitcoin ETFs pulled in a total of $853.54 million for the week that concluded on August 7. This represents their largest weekly collection of funds in nearly four months.

The funds experienced positive inflows during every session of the week. The momentum began with $170.09 million on Monday, followed by $211.49 million on Tuesday and $244.42 million on Wednesday, before demand began to ease as the week closed. This weekly total exceeded the approximately $824 million gathered during the week of April 24 and was the most significant since the week ending April 17, which saw Bitcoin funds attract about $996 million.

BlackRock’s iShares Bitcoin Trust, known as IBIT, was the clear leader during this latest inflow period, securing roughly $693 million of the weekly sum. This means the world's largest asset manager captured over four-fifths of all new money flowing into the spot Bitcoin funds.

These recent inflows contribute to the impressive scale the products have achieved following their landmark US debut in January 2024. The entire group of funds has now seen cumulative net inflows surpass $52 billion and currently manages approximately $80 billion in net assets.

Custody Concerns and Market Reaction

The renewed interest in ETFs emerged just days after the disclosure of a security vulnerability impacting Coldcard hardware wallets, which brought the issue of custody to the forefront of the ETF rebound.

Researchers at TRM Labs have estimated that, beginning on July 30, attackers successfully drained about 1,816 BTC, valued at around $116 million, from more than 5,200 addresses. As investigators continue to trace the stolen funds, other estimates have suggested losses are closer to $130 million.

Bloomberg Intelligence ETF analyst Eric Balchunas highlighted the timing of the fund flows in relation to the Coldcard losses, although he did not go so far as to assert that investors affected by the self-custody breach had moved their assets directly into ETFs.

Balchunas proposed that the security failure could make institutional custody a more appealing option for investors whose main goal is long-term Bitcoin exposure, rather than using the digital asset for transactions or censorship-resistant payments. He argued that for this group of investors, the security frameworks offered by large financial institutions might become increasingly difficult to ignore after a failure involving hardware explicitly designed to keep Bitcoin separate from the traditional financial system.

While no direct evidence yet proves that the Coldcard breach caused this week's ETF inflows, the timing has undeniably renewed the debate over the trade-offs between self-custody and institutional custody, just as regulated Bitcoin funds are experiencing their highest demand in months.

Ethereum ETFs Mirror Bitcoin's Success

Ethereum-focused ETFs also demonstrated an even more pronounced recovery. These funds collected $244.94 million, marking their best week since April and extending a streak of positive weekly inflows to five consecutive periods.

This consistent run has now brought approximately $566 million into the Ethereum products, representing their longest weekly inflow streak of the year. It is also their most extended since a remarkable 14-week period between May and August 2025, which saw the funds attract nearly $10 billion.

In contrast to the Bitcoin funds, the Ethereum ETFs began the week with a net outflow of $11.42 million on Monday. However, demand reversed course dramatically soon after. Investors poured about $53.75 million into the funds on Tuesday, $60.86 million on Wednesday, and $92.15 million on Thursday, with an additional $49.60 million entering on Friday.

Once again, BlackRock was responsible for the bulk of the buying activity. Its iShares Ethereum Trust, or ETHA, attracted approximately $203 million throughout the week, which was equivalent to more than 80% of the category’s total inflows.

This concentration of funds means that the strongest week for both Bitcoin and ETH ETFs since April was overwhelmingly a BlackRock narrative. The IBIT and ETHA funds together absorbed about $896 million, representing more than four-fifths of the nearly $1.1 billion that flowed into the two groups combined. This revival in demand signifies a sharp turnaround from the weaker flows seen for much of the summer, providing the clearest signal in months that investors are once again building their exposure to crypto assets through Wall Street’s regulated investment vehicles.