Index
Quantum Solvency Index
Market quantum solvency
25.0%
Of 1,268,752 BTC scored across 15 reserves, weighted by what is on-chain, this share is not behind a key that has already been revealed. One number, recomputed from every snapshot below, signed when served.
Proof of Reserves answers one question: do the coins exist. This index answers the next one: how much of a reserve would still be its owner’s once a quantum computer can recover a private key from a public one. Quantum solvency is the share of a reserve not sitting behind a public key that is already revealed on-chain. Every row is scored from the holder’s own published address set, read against public chain data, and the index is signed when served.
| Quantum solvency | Reserve | On-chain total | Exposed | Practical risk | Disclosure | Custody and signatures | Cost to move | |
|---|---|---|---|---|---|---|---|---|
| 100.0% | El Salvador Strategic Bitcoin Reserve Sovereign reserve · 20 of 20 published addresses read Source: ONBTC treasury catalogue, bitcoin.gob.sv (live) | 7,776 BTC | 0.0% 0 BTC in 1 key | no concentrated exposed key | Live endpoint read 55 days ago | 100% never spent 1,665 signatures, none repeated | about $0 1 outputs, 0.00% of a day’s blocks | detail |
| 99.8% | Twenty One Capital Corporate treasury · 4 of 13 published addresses read, covering 100.00% of the declared balance Source: Twenty One treasury dashboard, xxi.mempool.space (live) | 43,513 BTC declared 43,513 BTC | 0.2% 88 BTC in 1 key | 1 key ≥ 10 BTC largest 88 BTC | Live endpoint read 42 days ago | 100% never spent 89 signatures, none repeated | about $1 6 outputs, 0.00% of a day’s blocks | detail |
| 61.9% | cbBTC custody reserve Wrapped-asset custodian · 44 of 44 published addresses read Source: cbBTC proof of reserves, coinbase.com (2026-09-28) | 95,740 BTC | 38.1% 36,500 BTC in 24 keys | 13 keys ≥ 10 BTC largest 8,002 BTC | Months old 43 days old | 39% single key, 61% never spent 418 signatures, none repeated | about $16 189 outputs, 0.01% of a day’s blocks | detail |
| 46.9% | OKX Exchange · 1236 of 4974 published addresses read, covering 99.84% of the declared balance Source: OKX proof-of-reserves reserves file, report 500375535 (2026-08-11, height 961,893) | 143,248 BTC declared 142,323 BTC | 53.1% 76,114 BTC in 1095 keys | 63 keys ≥ 10 BTC largest 6,571 BTC | Addresses withdrawn 91 days old | 4% single key, 49% multisig (2-of-2, 2-of-3), 48% never spent 2,816 signatures, none repeated | about $1,411 12,364 outputs, 1.2% of a day’s blocks | detail |
| 46.8% | Bitstamp Exchange · 201 of 201 published addresses read Source: Bitstamp wallet transparency endpoint, updated daily (2026-09-30) | 24,432 BTC | 53.2% 12,990 BTC in 87 keys | 21 keys ≥ 10 BTC largest 1,132 BTC | Months old 41 days old | 67% multisig (2-of-3), 33% never spent 378 signatures, none repeated | about $14 120 outputs, 0.01% of a day’s blocks | detail |
| 23.5% | Bitwise Bitcoin ETF (BITB) ETF custody · 65 of 65 published addresses read Source: BITB wallet addresses, bitbetf.com (live) | 38,306 BTC declared 38,306 BTC | 76.5% 29,289 BTC in 50 keys | 50 keys ≥ 10 BTC largest 866 BTC | Live endpoint read 42 days ago | 73% single key, 25% never spent, rest not readable 473 signatures, none repeated | about $8 98 outputs, 0.01% of a day’s blocks | detail |
| 18.2% | Metaplanet Corporate treasury · 47 of 82 published addresses read, covering 99.96% of the declared balance Source: Metaplanet treasury dashboard, metaplanet.mempool.space (live) | 42,982 BTC declared 43,000 BTC | 81.8% 35,157 BTC in 43 keys | 43 keys ≥ 10 BTC largest 1,500 BTC | Live endpoint read 42 days ago | 78% single key, 20% never spent, rest not readable 489 signatures, none repeated | about $4 48 outputs, 0.00% of a day’s blocks | detail |
| 16.8% | Binance Exchange · 54 of 54 published addresses read Source: Binance proof-of-reserves wallet address file, audit PR01SEP26 (2026-09-01, height 964,957) | 650,244 BTC declared 640,617 BTC | 83.2% 540,961 BTC in 35 keys | 18 keys ≥ 10 BTC largest 248,598 BTC | Months old 70 days old | 83% single key, 17% never spent 1,350 signatures, none repeated | about $968 8,854 outputs, 0.80% of a day’s blocks | detail |
| 1.8% | WBTC custody reserve Wrapped-asset custodian · 92 of 109 published addresses read, covering 99.86% of the declared balance Source: WBTC proof-of-reserve API, openapi.wbtc.network (live) | 116,350 BTC declared 116,512 BTC | 98.2% 114,275 BTC in 89 keys | 89 keys ≥ 10 BTC largest 3,013 BTC | Live endpoint read 42 days ago | 100% multisig (2-of-3) 134 signatures, none repeated | about $48 470 outputs, 0.04% of a day’s blocks | detail |
| 0.0% | BitMEX Exchange · 131 of 131 published addresses read Source: BitMEX proof of reserves, public S3 bucket (2026-05-12) | 7,555 BTC declared 14,453 BTC | 100.0% 7,555 BTC in 11 keys | 2 keys ≥ 10 BTC largest 6,945 BTC | Over six months old 182 days old | 100% single key 10,364 signatures, none repeated | about $1 10 outputs, 0.00% of a day’s blocks | detail |
| 0.0% | Backpack Exchange · 6 of 6 published addresses read Source: Backpack public wallets endpoint (2026-09-30) | 373 BTC | 100.0% 373 BTC in 2 keys | 2 keys ≥ 10 BTC largest 285 BTC | Months old 41 days old | 76% multisig (3-of-5, 3-of-4), 24% Taproot key path 116 signatures, none repeated | about $0 3 outputs, 0.00% of a day’s blocks | detail |
| 0.0% | sBTC peg wallet Protocol · 1 of 1 published addresses read Source: sBTC documentation, docs.stacks.co (2026-09-30) | 2,485 BTC | 100.0% 2,485 BTC in 1 key | 1 key ≥ 10 BTC largest 2,485 BTC | Months old 41 days old | 100% Taproot key path 26 signatures, none repeated | about $0 1 outputs, 0.00% of a day’s blocks | detail |
| 0.0% | HTX Exchange · 7 of 7 published addresses read Source: HTX monthly proof-of-reserves snapshot, GitHub (2026-09-30) | 7,830 BTC declared 8,083 BTC | 100.0% 7,830 BTC in 7 keys | 6 keys ≥ 10 BTC largest 5,863 BTC | Months old 41 days old | 99% single key, 1% multisig (2-of-3) 2,178 signatures, none repeated | about $229,824 1,534,096 outputs, 190.7% of a day’s blocks | detail |
| 0.0% | Bybit Exchange · 21 of 21 published addresses read Source: Bybit proof-of-reserves audit report (Hacken), bybit.com (2026-05-27) | 19,717 BTC | 100.0% 19,717 BTC in 20 keys | 15 keys ≥ 10 BTC largest 5,400 BTC | Months old 167 days old | 100% single key 96 signatures, none repeated | about $50 368 outputs, 0.04% of a day’s blocks | detail |
| 0.0% | Binance-Peg BTC (BTCB) collateral Wrapped-asset custodian · 1 of 1 published addresses read Source: Binance proof of collateral for B-tokens (live) | 68,200 BTC declared 68,200 BTC | 100.0% 68,200 BTC in 1 key | 1 key ≥ 10 BTC largest 68,200 BTC | Live endpoint read 42 days ago | 100% single key 54 signatures, none repeated | about $12 116 outputs, 0.01% of a day’s blocks | detail |
| 0.0% | Bitwise Ethereum ETF (ETHW) ETF custody · 13 of 13 published addresses read Source: ETHW wallet addresses, ethwetf.com (live) | 111,267 ETH declared 111,273 ETH | 100.0% 111,267 ETH in 8 keys | 8 keys ≥ 100 ETH largest 20,865 ETH | Live endpoint read 41 days ago | 100% single key 168 signatures, none repeated | one transaction per account | detail |
| 0.0% | Binance-Peg ETH collateral Wrapped-asset custodian · 1 of 1 published addresses read Source: Binance proof of collateral for B-tokens (live) | 454,999 ETH declared 584,999 ETH | 100.0% 454,999 ETH in 1 key | 1 key ≥ 100 ETH largest 454,999 ETH | Live endpoint read 41 days ago | 100% single key 97 signatures, none repeated | one transaction per account | detail |
Reading the numbers. Exposed means the public key behind a balance is already recoverable from public chain data; it does not mean the funds can be taken with current hardware, and it cannot be undone except by moving the coins. An exchange hot wallet must spend constantly, which reveals its key, so some exposure is structural for any exchange; the question is whether balances are swept to fresh keys or left to accumulate behind one revealed key. The practical-risk column shows the part that would actually be worth attacking: an attacker must recover each key separately.
Where the address sets come from.Only from the holder itself: an exchange’s own proof-of-reserves file, a sovereign’s own catalogue, never from third-party wallet labels. Where the holder declares balances, the declared total is shown next to what the chain says. Addresses the public explorer could not read at snapshot time are counted, not guessed. Snapshots are dated; each entry re-runs on a schedule and the method is the same as the exposure report.
Not yet scorable: the spot ETFs
Every major spot bitcoin and ether ETF now tells its investors, in its own SEC filing, that quantum computing could compromise the wallets holding the trust’s coins. Not one has published the addresses that would let anyone check how exposed those wallets are. The disclosure exists; the substantiation does not. Any custodian that publishes its address set is scored here, free, within a day.
| Quantum solvency | Fund | What the filing says |
|---|---|---|
| unverifiable addresses not published | iShares Bitcoin Trust (IBIT) BlackRock · custodian: Coinbase Custody Trust Company; Anchorage Digital Bank as additional custodian | “sufficiently powerful quantum computers ... could allow a malicious actor to compromise the wallets holding bitcoin owned by the Trust” |
| unverifiable addresses not published | iShares Ethereum Trust (ETHA) BlackRock · custodian: Coinbase Custody Trust Company | “The extent of this risk may depend on, among other things, whether public keys have been exposed ... and the wallet-generation, key-management and transaction-signing practices of the Ether Custodian” |
| unverifiable addresses not published | Grayscale Bitcoin Trust (GBTC) Grayscale · custodian: Coinbase Custody Trust Company; Anchorage Digital Bank as additional custodian | “derive private keys from publicly available public keys, potentially allowing malicious actors to forge transaction signatures and misappropriate Bitcoin” |
| unverifiable addresses not published | Fidelity Wise Origin Bitcoin Fund (FBTC) Fidelity · custodian: Fidelity Digital Asset Services (per the fund) | “cites Google Quantum AI research of 31 March 2026 that the computing power needed to break the encryption protecting bitcoin may be significantly lower than previously believed” |
| unverifiable addresses not published | Bitwise Bitcoin ETF (BITB) Bitwise · custodian: per the fund | “In such circumstances, malicious actors might be able to steal bitcoins held by others” |
| unverifiable addresses not published | Franklin Bitcoin ETF (EZBC) Franklin Templeton · custodian: per the fund | “There can be no assurance that these risks will be sufficiently mitigated with protective measures” |
Hold a reserve and want the signed version, on a schedule, checked against your own policy? That is a reserve attestation. The signed index is also served as JSON at /api/quantum-solvency.
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