Dossier 05 Source-led history · Edition 1.0
The Mt. Gox Collapse: Losses, Wallets and a Decade of Repayments
Mt. Gox made the distinction between an on-chain coin and an exchange liability impossible to ignore. The company’s own figures changed within weeks, and a full account must preserve the date, status, and uncertainty attached to each number.
In this dossier
At a glance
Verified record
| Date | Documented quantity or action | Status of figure | What the record establishes | Source |
|---|---|---|---|---|
| 28 February 2014 | ≈850,000 BTC reported lost | Company estimate in filing announcement | Approximately 750,000 BTC was attributed to customer balances and approximately 100,000 BTC to the company. | [1] Civil-rehabilitation filing announcement |
| 7 March 2014 | 199,999.99 BTC located | Company-reported wallet balance | Mt. Gox said a rescan found the balance in an old-format wallet used before June 2011. | [2] Old-wallet balance announcement |
| 14–15 March 2014 | Located coins moved offline | Company-reported custody action | Mt. Gox said it moved the located coins from online to offline wallets and reported the movements to the court and supervisor. | [2] Old-wallet balance announcement |
| 20 March 2014 | ≈202,000 BTC total then held | Company provisional holding figure | The total combined the located wallet with approximately 2,000 BTC previously known. | [2] Old-wallet balance announcement |
| 20 March 2014 | ≈650,000 BTC estimated missing | Revised company estimate | The revision subtracted the newly located amount and remained expressly subject to investigation. | [2] Old-wallet balance announcement |
| June–July 2024 | Repayments scheduled to begin | Trustee notice under rehabilitation plan | The trustee announced bitcoin and bitcoin-cash transfers through designated exchanges beginning in July. | [5] Commencement of repayments notice |
| 21 August 2024 | Further repayment notice | Trustee proceeding update | The official archive recorded an additional notice concerning repayments in bitcoin and bitcoin cash. | [3] Official Mt. Gox proceedings archive |
An exchange balance became the dominant way many users encountered bitcoin
Mt. Gox began outside finance and evolved into a major bitcoin trading venue. Customers deposited sovereign currency or bitcoin, traded against entries in the exchange’s internal database, and requested withdrawals through systems the company controlled. That arrangement made trading convenient while replacing direct control of private keys with a claim against an operator.
The distinction is visible in the records each system produces. Bitcoin’s blockchain can show transfers to and from addresses, but it does not contain Mt. Gox’s complete customer ledger, contractual obligations, banking balances, or authorization controls. Conversely, an account statement can show that the exchange owes a customer without proving that matching bitcoin remains under the exchange’s control.
A withdrawal crisis became a balance-sheet crisis
In February 2014 Mt. Gox suspended bitcoin withdrawals and publicly discussed transaction malleability. Transaction malleability was a real property of then-standard transactions, but the existence of that protocol behavior did not establish the size, timing, or cause of the company’s asset shortfall. The later civil-rehabilitation filing disclosed a much broader inability to meet liabilities.
On 28 February, the company announced its application for civil rehabilitation in Japan and reported that almost all of roughly 850,000 BTC it said it held had disappeared. The total was divided approximately into 750,000 BTC corresponding to user balances and 100,000 BTC belonging to Mt. Gox. These were the company’s initial figures, not a completed forensic accounting.
An old-format wallet changed the estimate within three weeks
Mt. Gox’s 20 March notice said that wallets believed empty were rescanned after the filing. On 7 March, an old-format wallet used before June 2011 was found to contain 199,999.99 BTC. The company said it reported the discovery through counsel and moved the coins into offline storage between 14 and 15 March.
The discovery raised reported holdings to approximately 202,000 BTC, including about 2,000 BTC already known. Mt. Gox accordingly revised the amount estimated to have disappeared from approximately 850,000 to approximately 650,000 BTC. The notice itself warned that both cause and exact amount remained under investigation. A responsible history preserves that warning every time it reproduces the revised figure.
Wallet movements are evidence, but attribution needs an external bridge
Once an address is reliably attributed to the estate, blockchain records can independently show transaction identifiers, amounts, times, and later destinations. They can help reconcile reported custody movements and trustee distributions. The chain cannot itself prove why a transaction occurred, which customer liability it satisfied, or whether every attributed address belongs to the same legal entity.
This limitation is especially important when describing the missing coins. Public tracing can identify clusters and flows under stated assumptions, but it should not convert a provisional company estimate into a proven theft total or assign an actor without judicial or documentary support. The highest-confidence ledger is a dated reconciliation of official figures beside verifiable transactions, with the two evidence types kept distinct.
The creditor process lasted far longer than the exchange
The proceedings shifted from bankruptcy to civil rehabilitation, allowing distributions under a court-approved plan rather than a simple liquidation at the earlier yen value of claims. Creditors had to navigate claim recognition, repayment elections, identity checks, and designated exchanges. The legal claim and the on-chain asset were connected through a trustee-administered process, not by Bitcoin automatically returning funds.
On 24 June 2024, the rehabilitation trustee announced that bitcoin and bitcoin-cash repayments would begin through exchanges from early July after technical, compliance, and information checks. Subsequent notices documented implementation by exchange. The announcement proves commencement of the distribution process, not that every creditor had been repaid or that every disputed claim was resolved on that date.
Continuous block production did not make customers whole
Bitcoin’s consensus continued to operate while Mt. Gox failed. That distinction is analytically necessary: the exchange’s internal accounting and custody controls were not Bitcoin’s consensus mechanism. It is also insufficient as consolation. Customers experienced a loss of access and years of legal uncertainty even though their losses did not stop block validation.
Mt. Gox therefore belongs in Bitcoin history as an infrastructure failure with system-wide consequences. It altered perceptions of exchange solvency, private-key control, and the legal status of custodial claims. The enduring lesson is not the slogan ‘not your keys’ by itself, but the need to identify exactly which ledger records ownership, which party can authorize movement, and which remedy exists if those records diverge.
How Mt. Gox’s own bitcoin accounting changed
Every figure is kept in the form and status used by the company or trustee; subtraction does not turn a provisional estimate into a final forensic finding.
| Reported date | User-balance BTC | Company BTC | Located or held BTC | Estimated missing BTC | Document status |
|---|---|---|---|---|---|
| 28 February 2014 | ≈750,000 | ≈100,000 | Not yet included | Almost all of ≈850,000 | Initial civil-rehabilitation announcement |
| 20 March 2014 | Original component unchanged | Original component unchanged | 199,999.99 newly located; ≈202,000 total held | ≈650,000 | Revised provisional company estimate |
| 24 June 2024 | Creditor claims governed by plan | Estate-controlled holdings | Repayment transfers prepared | Not restated as a new loss estimate | Trustee implementation notice |
Evidence discipline
What the record establishes
Mt. Gox initially reported almost all of approximately 850,000 BTC missing.
[1] Civil-rehabilitation filing announcement · [2] Old-wallet balance announcementThe company located 199,999.99 BTC in an old-format wallet and then estimated approximately 650,000 BTC remained missing.
[2] Old-wallet balance announcementThe rehabilitation trustee announced bitcoin and bitcoin-cash repayments beginning through designated exchanges in July 2024.
[5] Commencement of repayments notice · [3] Official Mt. Gox proceedings archiveMt. Gox customer balances were custodian liabilities rather than customer-controlled on-chain outputs.
[1] Civil-rehabilitation filing announcement · [2] Old-wallet balance announcementLimits
What this record does not establish
- The 850,000, 202,000, and 650,000 BTC figures were company-reported and provisional; label them by date and never present them as one final audit.
- Locating an old wallet reduced the estimated shortfall but did not restore customers’ direct control or resolve their claims.
- On-chain attribution depends on documentary or evidentiary links between addresses and the estate; blockchain data alone does not identify a legal owner.
- A repayment announcement does not establish that every creditor has received funds.
Source register
Primary records and technical references
Retrieved and reviewed 8 August 2026- Civil-rehabilitation filing announcementMtGox Co., Ltd. · primary company and legal notice
The filing date, stated liabilities and assets, and initial reported bitcoin shortfall.
Open source - Old-wallet balance announcementMtGox Co., Ltd. · primary company notice
The 199,999.99 BTC discovery, offline movement, approximately 202,000 BTC holding, and revised approximately 650,000 BTC estimate.
Open source - Official Mt. Gox proceedings archiveMt. Gox Rehabilitation Trustee · primary proceeding archive
Dated trustee notices, plan administration, deadlines, and repayment updates.
Open source - Repayment procedures noticeMt. Gox Rehabilitation Trustee · primary trustee notice
The available repayment elections and registration process for creditor payee information.
Open source - Commencement of repayments noticeMt. Gox Rehabilitation Trustee · primary trustee notice
The planned start of bitcoin and bitcoin-cash repayments through designated exchanges in July 2024.
Open source
Cite this dossier
A stable, versioned reference
Degrees of Satoshi editorial project. “The Mt. Gox Collapse: Losses, Wallets and a Decade of Repayments.” Degrees of Satoshi, version 1.0, 8 August 2026. https://degrees-of-satoshi.pages.dev/history/mt-gox-collapse/
Contemporary primary records are preferred. Protocol behavior, business failures and government policy are treated as separate evidence categories. Interpretive claims are explicitly bounded; corrections should cite a source at least as strong as the record being revised.
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