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.
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.
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.
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.
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.