Key Takeaways
Blackrock’s IBIT held 734,762 bitcoin worth $48 billion as of July 15, 2026.Coinbase Custody holds bitcoin for most spot ETFs, creating a single point of failure across the market.The SEC’s 2025 in-kind redemption approval cut forced selling but left custody risk unresolved.
Blackrock‘s Ishares Bitcoin Trust, known as IBIT, is the largest of the group by a wide margin. As of July 15, 2026, the fund held 734,762 bitcoin worth $48 billion, according to Blackrock’s own holdings disclosure.
Fidelity’s Wise Origin Bitcoin Fund, Grayscale’s Bitcoin Trust, and several others account for most of the remaining supply.
A Trust, Not a Bank Account
These funds are not registered investment companies under the Investment Company Act of 1940. They are Delaware statutory grantor trusts. That distinction matters because 1940 Act funds carry custody rules, leverage limits, and governance requirements that spot bitcoin ETFs do not.
Each share represents a fractional interest in the trust’s net assets, mostly bitcoin held by a custodian. Shareholders do not own specific coins and hold no direct claim against the sponsor. They own a beneficial interest in the trust itself.
A typical structure splits responsibility among several parties:
Sponsor, such as Ishares Delaware Trust Sponsor LLC for IBIT, which oversees the trust and can direct the trustee. Grayscale Investments Sponsors, LLC is GBTC’s sponsor. Trustee, like IBIT’s Blackrock Fund Advisors, which handles daily operations and share creation and redemption. Custodian, primarily Coinbase Custody Trust Company, which holds the bitcoin in segregated cold storage. Fidelity, Hashdex, and Vaneck use other custodians. Cash administrator, typically BNY Mellon, which handles fund accounting.
If Blackrock or Fidelity Fails
The trust is a separate legal entity from its sponsor. If the sponsor filed for bankruptcy, creditors of that sponsor generally could not reach the trust’s bitcoin. The trustee retains authority to keep the trust running or wind it down in an orderly way.
A sponsor’s collapse would likely trigger termination provisions written into the trust agreement. The trustee would sell the bitcoin, pay expenses and creditors, then distribute the remaining cash to shareholders through the Depository Trust Company. Trading could pause, and net asset value calculations could be disrupted while the process plays out, and shares could trade at a discount to the underlying bitcoin price before any liquidation closes.
Of course, this is a 100% theoretical as no major spot bitcoin ETF sponsor has failed since the funds launched in January 2024, so this process has no direct precedent to date. Filings rely on Delaware trust law rather than tested case history.
Custodian Failure Is the Bigger Risk
Most spot bitcoin ETFs concentrate custody with one company, Coinbase Custody Trust Company. Fidelity is one exception, using its own affiliate, Fidelity Digital Assets, while some funds (Vaneck and Hashdex) list Gemini Trust Company and Bitgo Trust Company as custodians.
Prospectus filings describe this exposure directly. If Coinbase Custody entered bankruptcy, a court could rule that segregated bitcoin held for ETF clients still counts as property of the custodian’s bankruptcy estate. If that happens, the trust becomes an unsecured creditor. An automatic stay would freeze recovery efforts while litigation unfolds, a process that could stretch on for years and return only a fraction of the fund’s value. A Coinbase collapse could prove catastrophic because, unlike the failure of a single sponsor or ETF, it could destabilize most spot bitcoin ETF issuers.
Filings acknowledge that the legal treatment of digital assets in a custodian bankruptcy remains, in their own words, relatively untested. New York’s Department of Financial Services has issued guidance supporting the idea that custody clients should be treated as beneficiaries rather than general creditors, but that guidance does not bind a federal bankruptcy court. The 2022 collapse of FTX, where commingled customer assets were pulled into bankruptcy proceedings, is the closest real-world example regulators and attorneys point to when weighing how a custodian failure might unfold.
Insurance Covers a Fraction of the Exposure
Coinbase maintains crime insurance covering roughly $320 million, shared across its institutional custody clients. Spot bitcoin ETFs collectively hold more than $100 billion in bitcoin. Custodian liability agreements often cap damages at a fixed amount, in some cases as low as $5 million, and exclude losses tied to negligence thresholds or force majeure events.
A brokerage account holding ETF shares carries SIPC protection up to $500,000, including $250,000 in cash, if the broker itself fails. That protection covers the shares as a security. It does not cover a decline in the trust’s bitcoin value caused by a custodian collapse, and there is no equivalent of FDIC insurance for the underlying bitcoin.
Four Ways This Could Play Out
Attorneys who write these prospectus risk sections generally sort the possibilities into three scenarios:
Sponsor fails, custodian stays intact. Assets remain largely protected. Shareholders likely face a temporary trading halt followed by an orderly liquidation or a transition to a new sponsor. Custodian fails, sponsor stays intact. This carries the highest risk of permanent loss and across several counterparties. The trust could be forced to litigate for years to establish a claim on the bitcoin. No failure, but sustained stress at either party. Shares could trade at a persistent discount to net asset value while investors price in the added risk, and creations or redemptions could become slower and more expensive.
In every scenario, retail shareholders cannot redeem shares directly for bitcoin. Only authorized participants can create or redeem in bulk, which means secondary market liquidity depends on those firms continuing to step in and arbitrage the price. Holding paper ETFs essentially means owning an IOU, and if the issuer fails, you cannot directly access the bitcoin.
What Comes Next for Investors
Regulators have made some structural improvements. The SEC approved in-kind creation and redemption for spot bitcoin ETFs in 2025, a change that reduces forced selling of bitcoin to meet cash redemptions. That improves efficiency but does not remove custody risk.
Prospectus disclosures point to a few practical steps investors can take on their own. Spreading holdings across funds with different custodians, such as pairing IBIT with FBTC, reduces exposure to any single custodian failure. Reading the risk-factor sections of prospectuses and watching for changes in custody arrangements through 8-K and 10-K filings are the main tools available to shareholders.
The bottom line drawn from the filings is a split one. A smaller sponsor failure looks survivable, with shareholders likely recovering cash tied to bitcoin’s price through an orderly wind-down. A custodian failure is the scenario the industry has not tested, and the one prospectuses warn about most directly, one where recovery could be delayed, partial, or, in a severe case, close to total loss.
The custodian failure scenario would send shockwaves through the market and extend well beyond a handful of ETF issuers. If Coinbase experienced serious custodial problems, the effects would almost certainly ripple across the price of bitcoin and the broader cryptocurrency market.
