Proof of reserves entered the vocabulary after 2022, when several lenders turned out not to have the assets clients believed they had. It is now used as a shorthand for safety, and that shorthand is doing more work than it can bear.
Two of the ten active general-purpose Bitcoin lenders we track publish a recurring third-party attestation covering client collateral. The lender with arguably the strongest custody structure in the set publishes none. Those two facts sit awkwardly together, and understanding why is more useful than a checkmark table.
Who publishes one
Ledn runs the longest programme in the category. It completed the first Bitcoin-backed lending attestation in January 2021 and has published on a recurring basis since, engaging The Network Firm LLP for reports every two quarters. The most recent covers 31 March 2026 and reports assets in excess of 100% of client liabilities. Critically, Ledn publishes a Merkle tree, so each client can verify that their own balance was part of the total being attested rather than taking the aggregate on faith.
Strike publishes a quarterly Agreed-Upon Procedures engagement performed by FGMK LLC under AICPA attestation standards, with the first report covering 31 December 2025 and the latest 31 March 2026. The engagement runs five procedures: that loan and collateral balances in Strike's records match its loan system, that the collateral exists on-chain at segregated addresses held by Strike Lending or its capital providers, that aggregate loan-to-value sits within the documented margin call threshold, and that total Bitcoin held equals total customer collateral. Strike reports all five completed with no exceptions. Borrowers holding 50 BTC or more can request a dedicated on-chain address and monitor the collateral themselves at any time.
Those two programmes are not equivalent. Ledn's covers a longer history and includes client-level verification. Strike's is more frequent and its procedures explicitly test the aggregate LTV against the margin threshold, which is a solvency-adjacent check most attestations skip.
Who does not, and what they offer instead
The absence of an attestation is not automatically a red flag, and this is where a simple checkmark table misleads.
Arch holds collateral with Anchorage Digital, a federally chartered bank regulated by the OCC, in segregated arrangements that Arch states are bankruptcy-remote from both Arch and Anchorage, with insurance and no rehypothecation. That is a structural protection an attestation cannot provide: it changes what happens to your collateral if the lender fails, rather than confirming what was in the wallet last quarter. As of August 2026 we are not aware of a published Arch reserves attestation.
APX Lending uses BitGo Trust, a qualified custodian, in segregated insured cold storage. Unchained does something different again: in a collaborative multisig you hold a key, so you can verify the collateral on-chain yourself continuously, which makes a periodic third-party count somewhat redundant.
SALT, Figure, CoinRabbit and Nexo hold collateral in lender-operated arrangements without a published recurring attestation. For CoinRabbit the custodian is not disclosed at all, which is the weakest position in the set on this axis.
Grouped by where the collateral actually sits, the set looks like this:
A multisignature arrangement where you hold one of the keys, so no single party can move the collateral alone.
Collateral sits with a regulated custodian, segregated from the lender's own funds.
The lender holds your bitcoin directly, with no third-party qualified custodian. Convenient, but the safety depends on the lender's own practices and solvency.
Lender facts on this page render live from our comparison database, last verified August 4, 2026. Figures refresh weekly; for the current set and your own loan size, see the comparison tool.
The four things proof of reserves does not tell you
It is a snapshot, not a monitor. An attestation says the assets were there on 31 March. It says nothing about 1 April. Between reports you are relying on the same trust you were relying on before, which is why frequency matters more than the existence of a single report.
Assets without liabilities is half the picture. Proving a lender holds 10,000 BTC is meaningless unless you also know what it owes. The strong version of the exercise is proof of reserves and proof of liabilities. A Merkle tree matters here for a specific reason: without client-level inclusion proof, a lender could pass an attestation while omitting some liabilities from the figure being attested.
Scope is set by the engagement, not by the word. "Proof of reserves" is not a standardised product. An Agreed-Upon Procedures engagement tests exactly the procedures agreed with the firm and nothing else, and the value depends entirely on what those procedures were. This is why Strike listing its five procedures publicly is worth more than a lender saying "audited" without naming the firm, the standard, or the tests.
It does not prove the coins are unencumbered. Collateral can exist on-chain, be counted correctly, and still be pledged elsewhere. Whether a lender rehypothecates is a terms question that an asset count does not answer, and it splits the field differently from custody model:
Collateral is not re-lent or reused. The failure mode behind the 2022 collapses is removed.
The lender may put your pledged bitcoin to work elsewhere while the loan is open.
Our no-rehypothecation comparison tracks that question on its own for exactly this reason.
How to weigh it against custody
The useful framing is that these two answer different questions, and you want both answered rather than one answered loudly.
| What it tells you | What it misses | |
|---|---|---|
| Custody model | Where the collateral sits, who can move it, what happens if the lender fails | Whether the collateral is actually there right now |
| Proof of reserves | The collateral existed and was counted on a date, by a named third party | What happens between reports, and what the lender owes |
On that basis the set sorts roughly into three groups. Ledn and Strike publish attestations, with Ledn adding qualified custody and Strike operating a pooled model with segregated on-chain addresses. Arch, APX and Unchained offer structural custody protection without a recurring attestation. The remainder offer neither, and Nexo additionally permits rehypothecation under its standard terms.
Nobody in the set currently offers the full combination of federally chartered custody, a recurring client-verifiable attestation, and published proof of liabilities. That is the honest state of the category in 2026, and any comparison telling you otherwise is grading on a curve.
Questions worth asking your lender
If you take one thing from this page, make it these five questions, and ask for the answers in writing.
- Who holds the collateral, by name, and is it segregated from your operating assets?
- Do your terms permit rehypothecation, and is that answer different for US clients?
- Do you publish a reserves attestation, by which firm, under which standard, and how often?
- Does it cover liabilities as well as assets, and can I verify my own balance was included?
- Is the collateral bankruptcy-remote from you and from the custodian?
A lender that answers all five plainly is giving you more than any badge on a marketing page. One that will not name its custodian has answered question one.
Where to compare
Strike vs Ledn puts the two attestation publishers side by side. Arch vs Ledn contrasts the strongest custody structure with the longest attestation history. For the underlying mechanics see where your Bitcoin actually goes during a loan, and for the full risk picture, are Bitcoin loans safe?. Every lender's custody model is a sortable column on the comparison tool.
This is not financial advice
borrow/on/bitcoin is a comparison publisher, not a lender, broker, or financial advisor. We may receive compensation from some lenders featured on this page, which does not influence our default ordering or the data we publish. Attestation programmes, custodians, and terms change without notice, and the reports referenced here were the most recent published at the time of writing. Verify current documentation directly with each lender before you borrow. A reserves attestation is not a guarantee of solvency and does not remove the risk of losing your collateral.