QuadrigaCX, Canada’s largest cryptocurrency exchange at its peak, collapsed in early 2019 after co-founder and CEO Gerald Cotten died in Jaipur, India on December 9, 2018, leaving 115,000 users locked out of wallets holding approximately C$215 million in cryptocurrency and cash. The platform had operated since December 2013, growing to serve hundreds of thousands of registered users across Canada and internationally. The exchange announced Cotten’s death publicly on January 14, 2019, claiming no other employee possessed the encryption passwords to the cold wallets. The exchange filed for creditor protection under Canada’s Companies’ Creditors Arrangement Act on January 31, 2019.
Subsequent investigation by the Ontario Securities Commission, completed in April 2020 and published June 11, 2020, determined that what appeared to be a tragic accident was in fact a long-running fraud. Cotten had been operating a Ponzi scheme for years: he created accounts under aliases, credited himself with fictitious cryptocurrency balances, traded against his own customers, and covered accumulating losses with incoming client deposits. The OSC calculated that C$169 million of the asset shortfall was attributable to Cotten’s fraudulent conduct, with approximately C$115 million arising directly from his fake-balance trading. No criminal conviction has ever been recorded — Cotten is officially deceased — and no assets approaching the scale of the losses have been recovered.
The 115,000 users who held active balances at collapse were predominantly ordinary Canadian retail investors, many of whom had deposited savings, retirement funds, and money exchanged from national currency into Bitcoin and Ethereum on a platform that projected institutional legitimacy. As of May 2023, creditors received an interim distribution of 13 cents on the dollar, calculated on claims worth C$303.1 million — a figure that reflects continuing losses in real terms as cryptocurrency prices moved over the intervening years.
Thodex, one of Turkey’s largest cryptocurrency exchanges, collapsed on April 20, 2021, when founder and CEO Faruk Fatih Özer froze all withdrawals, suspended the platform, and boarded a flight to Albania — leaving approximately 391,000 registered users locked out of accounts holding funds estimated at roughly $2 billion. The exchange had operated since 2017 under the name Koineks before rebranding as Thodex in March 2020. Özer was 27 years old at the time of the exit.
Turkish prosecutors launched an immediate investigation. Özer was arrested in Vlora province, Albania in August 2022 after more than 16 months as a fugitive. He was extradited to Turkey in April 2023. On September 7, 2023, an Istanbul court convicted Özer and several of his siblings of aggravated fraud, money laundering, and criminal organisation charges, and sentenced him to 11,196 years in prison — one of the longest sentences ever imposed in Turkey. On appeal, the Istanbul Regional Court of Justice upheld the fraud and money laundering convictions in early 2025 but dismissed the organised-crime charge and ordered a limited retrial on that element. Özer remained incarcerated pending the retrial. On November 1, 2025, he was found dead in Tekirdağ F-Type High Security Closed Penitentiary. Authorities reported he was discovered hanged in the bathroom; the Istanbul prosecutor’s office opened an investigation and the body was transferred to the Institute of Forensic Medicine. The cause of death remained under formal inquiry at the time of this report.
The estimated loss figure of $2 billion, widely cited by Turkish prosecutors and international media, reflects the claimed value of cryptocurrency held in Thodex accounts at the time of the freeze. Because Thodex operated as a closed order-matching system without publishing audited proof-of-reserves, the true value of cryptocurrency under management has never been independently verified from blockchain records. The figure should be treated as the prosecutors’ working estimate rather than a fully audited loss amount.
Africrypt, a South African cryptocurrency investment platform founded in 2019 by brothers Raees Cajee and Ameer Cajee, collapsed in April 2021 after the founders claimed a hack had drained investor wallets and then instructed clients not to report the incident to authorities — a step they framed as protecting an ongoing recovery effort. Within days of that announcement, both brothers were unreachable. Client funds were gone.
The collapse attracted global attention primarily because of a headline figure: early reports, including a widely cited Bloomberg article from June 2021, placed losses at $3.6 billion, a figure derived from the claimed Bitcoin holdings at peak valuations. That number has not been verified by any regulatory body or court-appointed investigator. The Financial Sector Conduct Authority (FSCA), South Africa’s markets regulator, estimated investor losses at approximately R200 million (around $12–15 million at 2021 exchange rates) based on formal complaints received. Court-appointed liquidators working from documented fund flows put the credible upper bound at roughly $223 million. Independent analysts have cited a $40–50 million range as the most supportable estimate given available records. The gap between $3.6 billion and verified figures is substantial; this entry uses the FSCA and liquidator ranges and notes the discrepancy.
As of early 2026, Raees and Ameer Cajee had returned to South Africa from their years abroad and were reported to be residing inside a gated estate in KwaZulu-Natal. No formal criminal charges had been filed in South Africa. One brother was arrested in Zurich, Switzerland in November 2021 and later released on bail to supervised residence. South African authorities have not effected a domestic arrest, and lawyers for investors reported difficulty serving legal papers as of early 2026.
MyCoin, a Hong Kong-based cryptocurrency trading operation, vanished in late January or early February 2015, leaving approximately 3,000 investors locked out of accounts they believed held Bitcoin contracts collectively valued at up to HK$3 billion (approximately US$386–387 million at prevailing exchange rates). The platform had presented itself as a Bitcoin trading exchange offering guaranteed returns of HK$1 million within four months on a standardised contract. In practice it operated as a pyramid scheme: early investors were paid from the deposits of newer ones, and the promised Bitcoin holdings either did not exist or were vastly overstated. When the scheme could no longer sustain itself, the operators — whose identities were never fully confirmed under publicly named directors — shut the platform without notice and disappeared.
Hong Kong’s Commercial Crime Bureau launched an investigation within days of the closure. Five suspects were arrested in Hong Kong in March 2015, including two brothers and three women charged with conspiracy to defraud. Separately, Taiwanese authorities arrested two linked suspects, including one individual later identified as a key operator in Taiwan, who was extradited back to face proceedings. Operators were also pursued in Thailand. The ROSTER entry for VT-004 records the status as Convicted, reflecting that legal proceedings against arrested operators concluded in conviction. Full public sentencing records in English were not available in the sources reviewed for this report; the convictions are established in published court records and press releases from Hong Kong and Taiwanese authorities.
MyCoin is significant as an early large-scale Asian exchange exit and as a case study in how traditional pyramid-scheme mechanics were adapted to cryptocurrency’s opacity and novelty. Its victim pool was concentrated among working-class Hong Kong residents recruited through established professional networks — real estate agents, insurance brokers, and legal firm clerks — who used existing client trust relationships to channel money into the scheme.
FCoin, a Chinese cryptocurrency exchange founded in May 2018 by Zhang Jian, a former chief technology officer of Huobi, permanently closed on February 17, 2020, after Zhang publicly announced that the exchange had accumulated a deficit of between 7,000 and 13,000 Bitcoin — worth up to $130 million at prevailing prices — which it was unable to cover. Zhang attributed the deficit to compounding errors in FCoin’s signature innovation, a “transaction-fee mining” reward model, combined with treasury management failures and an undisclosed buyback programme for the exchange’s native token. The platform did not suffer a hack, and Zhang did not immediately flee in the manner of a conventional exit-scam operator; he published an extended written explanation and stated his intention to use proceeds from future ventures to repay users. He then became effectively unreachable.
Users were paid nothing. Blockchain researchers at AnChain.AI reported in February 2020 that funds had been moved from FCoin’s cold wallets to unknown accounts in the days before the closure announcement, raising the question of whether the deficit narrative was genuine insolvency or a cover for a planned exit. Chinese authorities investigated but no formal criminal charges against Zhang have been publicly confirmed in Chinese or international legal records as of this writing. Zhang’s whereabouts and legal status remain undisclosed.
FCoin occupies an unusual position in the taxonomy of crypto custody failures: it sits in the contested territory between catastrophic negligence and deliberate fraud. The factual record supports both readings. This entry presents the documented facts and notes where the record is genuinely ambiguous.
WEX.nz, a Russian-operated cryptocurrency exchange registered in New Zealand, collapsed in mid-2018 with somewhere between $400 million and $500 million in user deposits missing. The platform had launched in September 2017 as a near-identical copy of BTC-e — a notoriously shadowy exchange seized by US and European authorities in July 2017 for facilitating billions of dollars in money laundering — and was operated by Russian national Dmitry Vasiliev. Within eleven months of launch, WEX froze withdrawals, shed its domain names, and went dark. Vasiliev was later arrested in Warsaw and extradited to the United States in mid-2025 to face charges of fraud and money laundering.
The WEX story is inseparable from BTC-e, but they are distinct events. BTC-e was founded around 2011 and operated for six years as one of the world’s largest cryptocurrency exchanges, processing more than $9 billion in transactions while deliberately serving criminal clients including ransomware operators and darknet marketplaces. Its operator, Alexander Vinnik, was arrested in Greece in July 2017. WEX.nz then appeared as an ostensible continuation of BTC-e — inheriting user balances, the trading interface, and much of the user base — but it operated only under Vasiliev’s direction and lasted less than a year before its own exit. The two cases involve separate operators, separate legal proceedings, and separate thefts; understanding that distinction is essential to understanding either.
The roughly 100,000 users who trusted WEX with their deposits had already survived the BTC-e shutdown and accepted Vasiliev’s reassurances that their balances were intact and the new exchange was legitimate. Most recovered nothing. As of mid-2026, Vasiliev is in US custody awaiting trial; no meaningful restitution has reached victims.
Bitgrail, a small Italian cryptocurrency exchange operated by Francesco Firano, collapsed in February 2018 after Firano announced that approximately 17 million Nano tokens — worth roughly $170 million at the time of the announcement — had been stolen from the platform. Firano initially framed the loss as an external hack and demanded that the Nano development team alter the blockchain to reverse the transactions, a demand the team publicly refused. Italian courts subsequently determined that the losses resulted from Firano’s own gross mismanagement, that he had known about early-stage thefts for months before disclosing them, and that he had personally extracted Bitcoin from the exchange in the days immediately before making the loss public. The Florence Bankruptcy Court declared both Bitgrail and Firano personally bankrupt in January 2019, ordered him to repay users to the maximum extent possible from seized personal assets, and authorized the seizure of his property.
The platform had operated since approximately 2016 and became one of the world’s primary venues for trading Nano — then known as RaiBlocks — during the cryptocurrency bull market of late 2017 and early 2018. At the peak of the bull market, Nano was among the most actively discussed alternative cryptocurrencies, and Bitgrail’s position as an early listing venue gave it disproportionate control over the market for a token with a large and passionate community. When the collapse came, approximately 230,000 registered users were affected, though the number with active balances at risk was a subset of that total.
Italian criminal authorities separately investigated Firano’s conduct and alleged he was directly responsible for the hacks, not merely negligent in preventing them. The distinction between criminal fraud and civil mismanagement — one carrying a criminal conviction and the other an obligation to repay — defined the legal proceedings for years. As of mid-2026, Firano had been declared civilly bankrupt and ordered to repay victims; criminal proceedings were initiated but a final criminal conviction and sentence remained to be confirmed through Italian court records for this reporting period.
Mt. Gox, a Tokyo-based cryptocurrency exchange that handled approximately 70% of all global Bitcoin transactions at its peak, filed for bankruptcy protection in February 2014 after disclosing the loss of approximately 850,000 Bitcoin — roughly 650,000 belonging to customers and 200,000 to the exchange itself — an amount worth approximately $460 million at 2014 prices and more than $7 billion at Bitcoin’s 2021 peak. The exchange had operated since 2010 under the ownership of French-born programmer Mark Karpelès, who acquired it from its original American founder Jed McCaleb in 2011. The collapse remains the largest theft of Bitcoin in the currency’s history by unit count and was the defining crisis of early cryptocurrency infrastructure.
Karpelès was arrested by Japanese police in August 2015 on charges including embezzlement and data manipulation. The Tokyo District Court acquitted him of embezzlement in March 2019 — finding insufficient evidence that he personally stole user funds — but convicted him of data manipulation for falsifying records to inflate the exchange’s holdings by approximately $33.5 million. He received a suspended sentence of two and a half years and served no prison time. The acquittal on the embezzlement charge does not resolve the question of what happened to 850,000 Bitcoin; it means only that prosecutors could not establish beyond a reasonable doubt that Karpelès personally took them. The Tokyo High Court upheld the conviction on appeal in 2020.
The recovery process has extended for more than a decade. In March 2014, approximately 200,000 BTC were found in an old wallet, reducing the confirmed missing total to approximately 650,000 BTC. Of the remaining estate, approximately 140,000 BTC were available for distribution; repayments to roughly 127,000 creditors began in July 2024 through Kraken and Bitstamp, with the deadline extended to October 2026. Japanese bankruptcy law valued claims in yen at 2014 rates, meaning creditors received only a fraction of the appreciated Bitcoin value — a structural inequity that generated ongoing legal disputes over estate surpluses.
ACX Exchange, the cryptocurrency trading platform operated by Melbourne-based Blockchain Global Limited under the domain ACX.io (associated with Bitcoin.com.au), collapsed in late 2019 when customers found themselves unable to withdraw funds or cryptocurrency assets. Total unsecured creditor claims lodged with liquidators reached A$58,648,886 as of October 2023, of which A$22,753,442 represented claims from former ACX Exchange customers — a figure regulators describe as likely understating actual user losses given that many affected account holders did not file formal claims. Blockchain Global entered voluntary administration in October 2021 and liquidators were formally appointed on February 11, 2022.
The platform was operated under the direction of co-founders and directors Sam Lee and Liang “Allan” Guo, alongside co-founder Vincent Vu. Liquidator reports filed with ASIC in November 2023 identified potential breaches of the Corporations Act by current and former officeholders. ASIC commenced a formal investigation in January 2024 and filed civil penalty proceedings against Allan Guo in the Federal Court. A further development came on June 3, 2026, when the Federal Court stayed those civil proceedings pending a decision by the Commonwealth Director of Public Prosecutions on whether to lay criminal charges — an indication that the evidentiary threshold for criminal prosecution was under active assessment. As of that date, Guo had departed Australia on September 23, 2024, following the expiry of travel restraint orders, and had not returned.
The roughly 22,000 individuals who filed creditor claims were ordinary Australian retail investors who had deposited cryptocurrency and fiat currency into what presented as a professionally managed exchange. Active since approximately mid-2016 under the Bitcoin.com.au brand, it positioned itself as part of Australia’s legitimate crypto infrastructure. Users who lost funds have received no distribution from the liquidation estate to date.
Cryptsy, a Florida-based cryptocurrency exchange founded in 2013 by Paul Vernon — known by his forum handle “Big Vern” — collapsed in January 2016 after Vernon secretly drained the exchange’s cryptocurrency reserves, abandoned his Florida home, and relocated to China. The theft he concealed had begun more than eighteen months earlier: on July 29, 2014, Vernon claimed hackers had stolen 13,000 Bitcoin and 300,000 Litecoin from Cryptsy’s hot wallets. He disclosed nothing to users and continued operating the exchange, covering the resulting shortfall with incoming deposits in a manner consistent with a Ponzi scheme. By the time he shut the exchange down via a mass email to users on January 13, 2016, at least $6.6 million in customer cryptocurrency was confirmed missing, and Vernon was already abroad.
A class-action lawsuit filed the same day as the closure by attorney David Silver resulted in U.S. District Judge Kenneth Marra appointing receiver Jim Sallah in April 2016 to administer what remained of Cryptsy’s assets. On July 27, 2017, Judge Marra entered a default civil judgment — case number 9:16-cv-80060, Southern District of Florida — finding Paul Vernon liable to the plaintiff class in the principal sum of $8,200,000. The court simultaneously declared that the 11,325.0961 Bitcoin stolen from customers on July 29, 2014, constituted property of the plaintiff class subject to the judgment. Vernon did not appear, did not respond to the complaint, and did not make any payment toward the judgment. As of the date of this report, he remains believed to be in the Liaoning province of China, where he has no credible extradition exposure under existing treaty arrangements between the United States and the People’s Republic of China.
The customers who lost funds were predominantly early cryptocurrency adopters and traders who had deposited Bitcoin, Litecoin, and other altcoins into an exchange that processed significant daily volume across hundreds of listed trading pairs. The receiver’s efforts to recover assets were hampered by the absence of documentation of where customer funds had gone, and the $8.2 million judgment has never been enforced.
Bitsane, a Dublin-registered cryptocurrency exchange that had been operating since 2016, vanished on June 17, 2019. Its website went offline, its Twitter and Facebook accounts were deleted, and emails to support addresses began bouncing as undeliverable. The platform had counted 246,000 registered users and a daily trading volume of approximately $7 million as recently as March 31, 2019. Neither the named CEO, Aidas Rupsys, nor the named CTO, Dmitry Prudnikov, responded to press inquiries, appeared before any regulatory authority, or made any public statement explaining the closure. The operators have not been publicly located, charged, or identified through any confirmed legal proceeding as of the date of this report.
The disappearance followed a pattern that had become familiar in the 2019 period of exchange failures: withdrawal failures that began weeks before the final closure, support communications that cited unspecified technical reasons, and a terminal event in which all public-facing infrastructure was simultaneously deleted. Users who had held cryptocurrency on the platform — primarily XRP, Bitcoin, and other digital assets — found their balances inaccessible with no recourse pathway. The exchange had gained particular prominence as an early trading venue for XRP (Ripple), having at one point been listed as one of Ripple’s approved exchanges, and a significant portion of the affected user base held XRP positions.
Individual losses documented in reporting ranged from several thousand dollars to a single documented case of $150,000 in XRP and Bitcoin held by one US-resident user. The aggregate dollar loss is not established in any public regulatory or court filing; estimates reported at the time ranged widely. The case remains unresolved: no criminal charges have been filed, no assets have been frozen by Irish or European regulators, and no recovery mechanism has been established for affected users.
MapleChange, a small Canadian cryptocurrency exchange that had launched in May 2018, announced on October 28, 2018 that it had suffered a hack in which all funds were drained from its hot wallets. The same day, the exchange deleted its Twitter account, its Discord server, its Telegram channel, and its website. The reported loss was 913 Bitcoin — approximately $5.9 million at the time — which the exchange attributed to a bug that allowed users to exploit the withdrawal system. No verifiable evidence of an external hack was ever produced. The exchange’s operators were never publicly identified through any confirmed name or legal proceeding, and no charges have been filed in connection with the incident.
The sequence of events on October 28 — hack announcement followed within hours by simultaneous deletion of every public-facing channel — was widely characterised by security researchers and the crypto press as an exit scam executed under the cover of a fabricated security incident. The anonymous internet investigation that followed the deletion identified an individual suspected to be behind the exchange, but no law enforcement body has publicly confirmed or acted on that identification. Approximately five months of operations and 913 Bitcoin in customer deposits were the total scope of the exchange’s existence.
The users who lost funds at MapleChange were cryptocurrency traders who had deposited Bitcoin, Litecoin, and other altcoins into a platform that had listed 62 trading pairs and was in the process of building a user base. Many had modest balances; some had more significant positions. The exchange had been in operation for only five months, had no known regulatory registration, no published team information, and no audited financial records.
Bitmarket.pl, Poland’s second-largest cryptocurrency exchange by trading volume, ceased all operations on July 8, 2019, posting a brief notice on its website attributing the closure to a sudden loss of liquidity. The platform had operated since approximately 2015 under the control of co-owners Tobiasz Niemiro and Marcin Aszkiełowicz, who had taken over an exchange that already carried an outstanding deficit of more than 600 BTC at the time of their acquisition. When the platform went offline, users found they could not access or withdraw an estimated 2,300 bitcoin — then worth approximately PLN 100 million ($25 million USD) — held in their accounts.
The District Prosecutor’s Office in Suwałki opened a criminal investigation, overseen by the Department of Combating Cybercrime of the Provincial Police Headquarters in Olsztyn. More than 400 users filed formal complaints, and prosecutors later concluded that from mid-2015 through July 7, 2019, the exchange’s operators had systematically misled customers about the financial condition of the platform. On September 12, 2019, Marcin Aszkiełowicz was formally charged with defrauding 525 users of assets totalling PLN 22.66 million ($5.8M), a charge carrying a maximum sentence of ten years’ imprisonment. He was additionally accused of defrauding a share buyer the same year by misrepresenting the company’s financial position. Polish prosecutors indicated the full scope of losses attributable to the period of operation was substantially larger.
Tobiasz Niemiro, the exchange’s other co-owner, was found dead on July 25, 2019, in a forest near Olsztyn, approximately three weeks after the exchange closed. Polish authorities and Gazeta Wyborcza, Poland’s leading national newspaper, reported the death as an apparent suicide by gunshot. Acquaintances publicly disputed that characterisation. No criminal conclusion regarding the circumstances of Niemiro’s death has been reported. He was 44 years old. The legal proceedings against Aszkiełowicz continued. No trial verdict has been publicly confirmed in available sources as of the time of this writing.
YouBit, a South Korean cryptocurrency exchange formerly operating under the name Yapizon, collapsed into bankruptcy on December 19, 2017, after sustaining two separate intrusions in the same calendar year that together stripped approximately 21 percent of its total assets. The April 2017 hack cost the exchange 3,816 bitcoin, valued at approximately $5 million at the time. The December 2017 hack — attributed by South Korean intelligence and independent security researchers to the North Korean state-linked Lazarus Group — removed a further 17 percent of remaining assets, estimated at between $7 million and $16 million in contemporary reporting. Upon filing for bankruptcy, the exchange’s parent company, Yapian, announced that users would receive an immediate payment equivalent to 75 percent of their holdings, with the balance subject to the bankruptcy process.
That 25 percent haircut, imposed unilaterally at the moment of failure, was not the end of the controversy. Yapian had obtained a cyber insurance policy from DB Insurance just 20 days before declaring bankruptcy. DB Insurance denied the claim, asserting that Yapian had violated its advance notice obligation — the standard requirement for policyholders to disclose material information that would affect the policy before purchasing it. The insurer’s denial was based on the inference that Yapian had known of existing vulnerabilities or risks at the time it took out coverage. Critics argued the insurance was obtained specifically to limit the operator’s financial exposure at bankruptcy, a charge Yapian denied.
The exchange briefly re-emerged in 2018 under the Coinbin brand following an acquisition, but that entity also collapsed in February 2019 after its CEO disclosed that a former Youbit executive — identified as a general manager named Lee — had embezzled company funds and deleted private keys controlling wallets holding approximately 100 ETH. Total losses at CoinBin’s bankruptcy were placed at $26 million. No criminal conviction of exchange operators in connection with the YouBit bankruptcy proceedings specifically has been confirmed in publicly available reporting; the CoinBin case generated separate embezzlement allegations against the named employee.
Coinroom, one of Poland’s most active retail cryptocurrency exchanges, executed an exit scam on April 2, 2019, notifying users via a brief email that the platform was terminating all contracts and that customers had approximately 24 hours to withdraw their holdings. Customers who did not act — or who tried and found their withdrawals blocked — lost deposits ranging from PLN 300 ($79) to PLN 60,000 ($15,660). Seconds after the deadline passed, the exchange’s website went dark, its phone lines went silent, and all social media accounts were deleted. The company’s director, Tomasz Zbigniew Wiewior, disappeared. Polish prosecutors opened a criminal investigation, but as of available reporting, no arrest or conviction of Wiewior has been publicly confirmed.
The exchange had been registered in 2016 and began operating its trading platform in 2017, offering Polish retail users a straightforward fiat-to-crypto on-ramp with PLN pairs for Bitcoin, Ethereum, and other major cryptocurrencies. It carried no regulatory oversight, operated without any mandatory capital reserve requirement, and maintained no deposit protection mechanism. Its user base was predominantly Polish, composed largely of retail investors making first or second cryptocurrency purchases, many of whom held balances equivalent to weeks or months of savings.
The April 2019 exit was not spontaneous. The sequence of preparation required — deleting social media profiles, disabling the website, shutting down telephone lines, and creating the infrastructure for Wiewior to leave the jurisdiction — constitutes coordinated pre-planning. Reporting from Polish financial publication Money.pl and others indicated that Wiewior was alleged to have established a company in Estonia prior to the closure, suggesting advance preparation for departure. No public charges have been filed against Wiewior in available reporting as of the time of this dossier, and no assets have been returned to depositors.