Crypto Industry Examines Limitations of Proof of Reserves Following FTX Collapse

Following the FTX collapse, the digital asset industry has increasingly turned to Proof of Reserves (PoR) to restore user trust. While PoR provides transparency for on-chain assets—with CoinMarketCap tracking $192.6 billion in reserves in June 2026—experts warn of severe limitations. PoR relies on point-in-time snapshots that can be gamed by temporary fund transfers, fails to prove exclusive key control, and completely ignores off-chain liabilities. Industry leaders emphasize that PoR is not a substitute for comprehensive financial audits or SOC1/ISAE 3402 control reports.

Proof of Reserves methodology

• ▪There are no professional audit standards currently established for conducting and reporting Proof of Reserves procedures.
• ▪Proof of Liabilities totals user balances, often hashed into a Merkle tree, allowing outside parties to verify totals without exposing individual account details.
• ▪Proof of Reserves is a disclosure method showing on-chain assets held by a crypto exchange or custodian to back customer balances at a specific point in time.

Snapshot timing manipulation risks

• ▪Proof of Reserves relies on a point-in-time snapshot, which ignores transactions and asset movements that occur before and after the snapshot date.
• ▪Exchanges can game Proof of Reserves by temporarily borrowing assets or moving funds just before the snapshot check.

Exchange reserve ratios

• ▪In July 2026, Phemex reported an average reserve ratio of 127.77% across BTC, ETH, USDT, and SOL, including 112.24% for BTC and 149.50% for ETH.
• ▪MEXC's July 2026 Proof of Reserves update, audited by Hacken, showed a BTC reserve ratio of 281%, covering 4,439.51 BTC of user holdings.
• ▪CoinMarketCap tracked approximately $192.6 billion in exchange Proof of Reserves in its June 2026 report, representing a 5.3% month-over-month decline.
• ▪In June 2026, USDT was the largest reserve asset tracked by CoinMarketCap at approximately $57.6 billion, with BTC second at around $55.5 billion.

User verification workflow

• ▪Users can verify their account balance inclusion in an exchange's liabilities total by downloading and running a Merkle proof or zk-STARK proof file.
• ▪To verify Proof of Reserves independently, users must check Merkle proofs, verify cryptographic signed messages from known wallets, and match balances on-chain.

Off-chain liability gaps

• ▪Unlike Proof of Reserves, SOC1 or ISAE 3402 Type 2 reports and full-scope consolidated financial audits provide assurance on internal controls and overall financial position.
• ▪Proof of Reserves cannot independently prove exclusive key control of the addresses holding the assets.
• ▪Proof of Reserves fails to capture off-chain liabilities, including bank-held fiat balances, lines of credit, rehypothecation deals, insurance coverage, or legal claims.

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