Does a Crypto ETF Change Your Risk or Just Who Holds It?

Key Takeaways

• Binance estimated its October breach at $6.3 billion
• ARKB custodians’ $685 million insurance covers all clients
• Coinbase Custody liability capped at $100M per address
• Coinbase says it custodies 80%-plus of ETF assets

In a November 5 analysis, Wei Wayne Miao, chief legal officer of 21Shares US, argued that registered vehicles built around qualified custodians and segregated assets can give investors stronger legal protection than an account at a trading venue. 21Shares US sponsors the ARK 21Shares Bitcoin ETF (ARKB), so that fund’s own filings are the most direct place to test the argument.

What the Binance breach tested

Binance estimated the incident’s impact at about $6.3 billion, said roughly $3 billion had been frozen, suspended deposits and withdrawals, and pledged that users would not bear the loss. The exchange has attributed the initial access to a compromised engineer’s laptop and said it found no evidence that wallet private keys leaked.

For Binance customers, the protection so far is the exchange’s decision to absorb the loss with its own money. That holds while the company stays solvent and willing to pay. An ETF investor relies on a different set of promises, made by several parties, and the 21Shares argument depends on how those promises behave when one party fails.

What an ARKB share legally gives you

Each ARKB share is a fractional, undivided beneficial interest in the trust’s net assets, according to the fund’s annual report for 2025. The trust owns the Bitcoin, and its custodians hold it on the trust’s behalf. The shareholder owns an interest in the trust, not a claim on particular coins. Coindoo has covered the practical side of that arrangement in its explainer on why a Bitcoin exchange-traded product differs from Bitcoin in a wallet.

The trust is also not an investment company. The SEC’s investor bulletin on spot Bitcoin and Ether products says they register under the 1933 and 1934 securities laws and are subject to antifraud rules. It also says they are not bound by the Investment Company Act of 1940, including its requirements on valuing and safeguarding fund assets, whatever their names suggest.

ARKB’s description of itself shows what that means in practice. The trust has no officers, directors or employees, so there is no fund board of the kind a registered fund answers to. Shareholders have no voting rights except where the sponsor grants them, and the sponsor is liable only for gross negligence, bad faith or willful misconduct.

This is where the 21Shares analysis needs a close reading. Two of the three safeguards it lists apply to registered funds and registered advisers: Section 17(f) of the 1940 Act and the custody rule under the Advisers Act. ARKB’s annual report says the trust is not registered under the 1940 Act and its sponsor is not registered with the SEC as an investment adviser. The fund’s protections come instead from its contracts and from its custodians’ own trust and banking charters.

Three ways a $10,000 position can shrink

The Securities Investor Protection Corporation covers missing securities and cash at a failed member brokerage up to $500,000 per customer, including $250,000 in cash. It restores what was in the account, not what the holdings were worth when bought. ARKB’s filing adds that the trust itself is not a SIPC or FDIC member, and that neither the trust nor its sponsor insures the Bitcoin.

Hypothetical $10,000 ARKB position, not a reported loss

Bitcoin drops 20%

Position: about $8,000 before fees and tracking differences

Claim against: nobody, because a price fall is a loss rather than a claim

The broker fails and shares are missing

Position: SIPC works to return the shares, valued at that day’s market price

Claim against: the broker’s estate, then SIPC within its limits

The trust loses 5% of its Bitcoin, unreimbursed

Position: about $9,500 at an unchanged price, with every share still in the account

Claim against: no one directly; the trust pursues the custodian and insurer

The first two outcomes would look the same for any stock held at a broker. The third is specific to a product whose value sits with custodians two steps removed from the investor, and it is the scenario the Binance breach brings to mind. ARKB’s filing describes how that layer is built.

Inside ARKB’s custody chain

ARKB spreads its Bitcoin across four custodians: Coinbase Custody Trust Company, BitGo Bank & Trust, Anchorage Digital Bank and BitGo New York Trust Company. Most of the coins sit in cold storage in segregated wallets, which the filing says are not commingled with the custodians’ own assets or those of other customers. The trust and its service providers are also barred from lending or pledging its assets, a restriction worth noting given the Celsius case discussed below.

A second pool carries more risk. Coinbase, Inc., acting as prime broker, holds a trading balance used for share creations, redemptions and expense payments. The filing describes that balance as an omnibus claim: a pro rata share of Bitcoin the prime broker holds for many clients, with no identifiable coins assigned to the trust. Coinbase is not required to keep it in cold storage or segregate it, and does not tell the sponsor how much of the pool sits in hot wallets. The balance is limited to what each transaction needs, but while it exists, it resembles an exchange account more than a vault.

ARKB’s custody contracts in figures

Up to $100 million

Coinbase Custody’s liability per cold storage address, and only for gross negligence, fraud or willful misconduct

12 months of fees

Cap on most direct damages under the BitGo and Anchorage agreements, with carve-outs for misconduct

$685 million

Aggregate theft insurance the four custodians report, shared with all of their clients

About $5 billion

Value of ARKB shares held by non-affiliates on June 30, 2025

Source: ARK 21Shares Bitcoin ETF Form 10-K for fiscal 2025, filed March 2, 2026

Set against one fund of that size, the insurance pool and liability caps are thin backstops, and every client of four firms draws on the same coverage. The filing warns that insurance may not cover the type of loss the trust suffers and that proceeds may have to be split with other customers. These are disclosed risks. Nothing in the report indicates that ARKB has lost any Bitcoin.

Regulation of the custodians does not close that gap. As Coindoo’s coverage of crypto trust charters and deposit insurance explains, a supervised custodian and an insured asset are separate things.

The exchange side: title on paper, keys with Coinbase

The 21Shares argument has a real precedent behind it. In its first-quarter 2022 report, Coinbase warned that customers’ crypto could be treated as property of its estate in a bankruptcy, which would make those customers general unsecured creditors. Chief executive Brian Armstrong said the disclosure followed new SEC accounting guidance, and that the legal protections had not yet been tested in court for crypto.

Coinbase’s current U.S. user agreement, last updated in December 2024, reads differently. It says title to supported assets stays with the customer, and that those assets are not Coinbase’s property or subject to its creditors’ claims. It also treats them as financial assets under California’s version of Article 8 of the Uniform Commercial Code, with Coinbase acting as a securities intermediary.

That clause weakens the sharpest version of the 21Shares case. The analysis credits institutional custody with treating the custodian as a securities intermediary rather than a debtor, and Coinbase’s retail agreement relies on the same legal construct. The real difference is operational. Coinbase keeps control of the private keys and may hold customer coins in shared addresses it controls. It has no obligation to create a segregated address for any user, although it keeps separate ledgers.

Contract wording decided the Celsius bankruptcy. In January 2023, Chief Judge Martin Glenn of the U.S. Bankruptcy Court for the Southern District of New York ruled that assets in Celsius Earn accounts belonged to the estate, because the Earn terms transferred title to the company (In re Celsius Network LLC, No. 22-10964). Coinbase’s terms say the reverse, but they have never been tested in a Coinbase insolvency. Binance customers sign agreements with different entities under different laws, and those terms would need the same reading.

Different tickers, same vault

Custody concentration also limits what spreading money across funds can achieve. In its third-quarter 2025 shareholder letter, Coinbase said it was the primary custodian for more than 80% of U.S. Bitcoin and Ether ETF assets. An investor who splits a position across several spot Bitcoin funds may be adding issuers without adding custodians.

ARKB is one of the funds that has diversified, yet Coinbase remains both one of its four custodians and its prime broker. The sponsor can add or drop custodians at its discretion and must disclose any change within four business days. The custodian list in an older prospectus can therefore be out of date.

Crypto Hack Recovery Has a Problem Bigger Than Stolen Keys

Does the 21Shares claim hold up?

Partly. An ARKB share is a security held at a broker and covered by SIPC if that broker fails. Most of the fund’s Bitcoin sits in segregated cold storage as the trust’s property, and the fund cannot lend it out. Those are concrete advantages over an omnibus exchange account, especially at a venue whose terms and governing law an investor has never read.

The strongest objection comes from the exchange side. Coinbase’s terms already give retail customers title and Article 8 treatment, and Binance has said it would cover the breach from its own funds. Both points are fair, yet both protections depend on the venue staying solvent and honoring its contract.

The ETF does not remove that kind of dependence; it moves it further down the chain. Losses at the custodian layer run into capped liability, shared insurance and a pooled trading balance, and the shareholder has no vote and no direct claim with which to pursue them. The next documents that could confirm or weaken this picture are Binance’s promised technical post-mortem and updated proof of reserves, and ARKB’s next annual report, which would record any change to its custodians, insurance or contract terms.

Search terms that locate the relevant clauses

Spot fund 10-K or prospectus

“Bitcoin Custodian”, “Trading Balance”, “aggregate liability”, “insurance coverage”, “not registered as an investment company”

Exchange user agreement

“title”, “omnibus”, “private keys”, “securities intermediary”, “creditors”