Proof of reserves, and the part it does not cover
After 2022, most large exchanges published proof-of-reserves pages. They are a genuine improvement on nothing at all, and they are also routinely described as something they are not: an audit.
What the cryptography actually does
A standard proof of reserves builds a Merkle tree of customer balances and publishes the root. Each customer can verify that their own balance is included in the total without seeing anyone else's. Alongside it, the exchange signs messages from its wallets to show control of assets.
Together these establish two things: total customer claims, and on-chain assets under the exchange's control at the moment of the snapshot.
The liabilities gap
Assets prove nothing about what the exchange owes elsewhere. A venue can hold coin fully matching customer balances while carrying large off-chain debt against those same assets. Proof of reserves does not see that, because the borrowing is not on the chain.
This is why a proof-of-reserves page is a solvency hint rather than a solvency statement, and why the strongest versions are signed off by an accounting firm that also examines liabilities.
| Question | Proof of reserves answers it? |
|---|---|
| Does the exchange control these coins? | Yes, at the snapshot moment |
| Is my balance in the published total? | Yes, verifiable by the customer |
| Does the exchange owe money elsewhere? | No |
| Were the coins borrowed for the snapshot? | No |
Reading one properly
Check the snapshot date and how often it is repeated — a single snapshot from eighteen months ago says little. Check whether a named firm attests to it. Check whether the wallet list is complete or a selection.
And verify your own balance in the tree if the exchange provides the tool. Few customers do, which is part of why the mechanism is weaker in practice than in design.
FAQ
Is proof of reserves the same as an audit?
No. It demonstrates assets and customer claims at a point in time; a financial audit examines liabilities, controls and going concern.
Can an exchange fake it?
Borrowing assets around the snapshot date produces a passing proof without matching real backing, which is why snapshot frequency and third-party attestation matter.