Robert Mitchnick, head of digital assets at BlackRock, said the firm is seeing overwhelming demand for spot Bitcoin ETFs, citing a recent wave of security breaches that have shaken confidence in self-custody among investors.
The remarks came as hackers stole more than $130 million in Bitcoin from thousands of cold wallets over recent days, with the Coldcard wallet hack accounting for a substantial portion of the losses. The breach exposed a key vulnerability in self-custody arrangements that had previously been marketed to retail investors as the gold standard for asset security.
Mitchnick made the comments during an appearance on Bloomberg's ETF IQ program, where Bloomberg's Eric Balchunas noted the hack could accelerate a shift toward exchange-traded products as an alternative to holding crypto directly. Spot Bitcoin ETFs, approved in the United States starting in January 2024, allow investors to gain Bitcoin exposure through traditional brokerage accounts without managing private keys or cold storage hardware themselves.
U.S. spot Bitcoin and Ethereum ETFs recorded their strongest weekly inflows since April 2026 in early August, pulling in $853.5 million during a single week. The figure represents a material uptick from typical weekly volumes, and capital is actively routing into these products.
Self-custody has long been positioned within the crypto industry as a core principle. Hardware wallets like Coldcard have marketed themselves as unhackable because they remain disconnected from the internet. The recent theft of $130 million across thousands of supposedly secure cold wallets contradicts that narrative and raises questions about either the security model itself or the operational practices of users storing funds in these devices.
BlackRock has been a major driver of spot Bitcoin ETF adoption since launching its iShares Bitcoin Trust in January 2024. The firm has not disclosed total assets in its Bitcoin ETF product, though industry data indicate spot Bitcoin ETFs collectively hold over $60 billion in assets under management as of August 2026.
The security incident and Mitchnick's statement reveal a potential structural shift in how crypto investors approach custody. If confidence in self-custody wanes materially, adoption of regulated products that offload custody responsibilities to financial institutions with insurance and compliance frameworks could accelerate. Mitchnick's framing of overwhelming demand indicates BlackRock expects this trend to persist.
The key number to monitor is the weekly inflow pace for spot Bitcoin ETFs in September and October 2026. If inflows sustain at or above the $800 million weekly run rate seen in August, it would indicate the custody concern has created a durable shift in investor behavior rather than a temporary response.
