What Was Mt. Gox? Definition, History, Collapse, and Future

What Was Mt. Gox?

Mt. Gox was a Tokyo-based cryptocurrency exchange that operated between 2010 and 2014. It was responsible for more than 70% of Bitcoin transactions at its peak. Although it is most commonly known as Mt. Gox, the exchange is sometimes referred to as MtGox or Mt Gox. The exchange declared bankruptcy in 2014, but it continued to be the subject of lawsuits and speculation for years.

Key Takeaways

  • Mt. Gox was a cryptocurrency exchange that operated between 2010 and 2014.
  • Mt. Gox once accounted for over 70% of all Bitcoin transactions.
  • In 2014, Mt. Gox was hacked and thousands of Bitcoins were stolen; the company filed for bankruptcy shortly thereafter.
  • In late 2021, creditors and the Tokyo District Court reached an agreement on the Mt. Gox rehabilitation plan, closing a seven and half year legal battle.

Early History of Mt. Gox

Jed McCaleb created the website that became the Mt. Gox exchange. It was initially a way for enthusiasts of the card game "Magic: The Gathering" to trade cards online.

The name Mt. Gox was created as an acronym for "Magic: The Gathering Online Exchange." The site was transferred to Mark Karpeles in 2011 in exchange for six months worth of revenue. Karpeles became the largest shareholder and CEO.

Mt. Gox was considered the world’s largest Bitcoin exchange at its peak. It handled 70% to 80% of the trading volume. Handling so many transactions gave Mt. Gox an outsized role in determining Bitcoin's market activity. For example, in 2013 it suspended trading for several days to cool down the market.

What Happened to Mt. Gox?

Its prominence in the cryptocurrency scene made it a target for hackers, and Mt. Gox experienced security problems several times during the years it operated. In 2011, hackers used stolen credentials to transfer Bitcoins. That same year, deficiencies in network protocols resulted in several thousand Bitcoins being “lost.”

In the months leading up to February 2014, customers expressed increasing frustration with problems withdrawing funds. Technical bugs prevented the company from having a firm grasp on transaction details, including uncertainty relating to whether Bitcoins had been transferred to customers’ digital wallets.

This issue was claimed to be the result of a bug in the Bitcoin software that allowed users to alter transaction IDs, sometimes referred to as “transaction malleability.” This claim has been disputed by the community, but the issue may be closed as an agreement was reached in late 2021.

The exchange suffered a fatal blow in February 2014. In early February 2014, the exchange suspended withdrawals after claiming to have found suspicious activity in its digital wallets. The company discovered that it had "lost" hundreds of thousands of Bitcoins. Reports on the number of coins lost ranged from 650,000 to 850,000.

While it was later able to locate 200,000 Bitcoins, the missing cryptocurrency profoundly destabilized the market. The value of the Bitcoins was estimated to be in the hundreds of millions, which pushed Mt. Gox into insolvency. It filed for bankruptcy in the Tokyo District Court and was ordered to liquidate in April 2014.

The estate that Mt. Gox’s assets were placed in owned more than 200,000 Bitcoin and Bitcoin Cash. In October 2019, Mt. Gox trustee Nobuaki Kobayashi extended the deadline for submitting claims to March 31, 2020.

There had been speculation that Russian hackers were behind the heist; there was also hope that some of the stolen Bitcoins could be recovered. CoinLab, a leading creditor against Mt. Gox, continued to pursue its multibillion-dollar breach of contract lawsuit against Mt. Gox.

In 2019, Mark Karpeles, the CEO of Mt. Gox, was found guilty of falsifying data to inflate holdings.

The Future of Mt. Gox

In November 2021, Mr. Kobayashi, the trustee for Mt. Gox, published an announcement after Japanese courts and Mt. Gox creditors reached an agreement on the Mt. Gox rehabilitation plan. The rehabilitation plan establishes a registration and compensation plan based on phases for different creditors.

Approved rehabilitation creditors with creditor codes can signup on the MT. Gox Online Rehabilitation Claim Filing System. Unfortunately, new rehabilitation claims cannot be filed using this system; the Tokyo District Court referred the rehabilitation draft to a resolution in February 2021, sealing the process and preventing the initiation of any new claims.

Whether Mt. Gox has a future in cryptocurrency remains to be seen. However, what is for certain is that a chapter in the cryptocurrency history book is now concluded.

What Happened to the Mt. Gox Bitcoins?

Only about 200,000 were ever recovered. The rest are lost or removed from the network.

How Many Bitcoins Did Mt. Gox Lose?

Reports range from 650,000 to 850,000, some of which belonged to the company and the rest to customers.

Is Mt. Gox Still Active?

Mt. Gox closed its website and filed for bankruptcy in 2014. Whether there will be an attempt at a reopening remains to be seen.

Investing in cryptocurrencies and other Initial Coin Offerings (“ICOs”) is highly risky and speculative, and this article is not a recommendation by Investopedia or the writer to invest in cryptocurrencies or other ICOs. Since each individual's situation is unique, a qualified professional should always be consulted before making any financial decisions. Investopedia makes no representations or warranties as to the accuracy or timeliness of the information contained herein.

Article Sources
Investopedia requires writers to use primary sources to support their work. These include white papers, government data, original reporting, and interviews with industry experts. We also reference original research from other reputable publishers where appropriate. You can learn more about the standards we follow in producing accurate, unbiased content in our editorial policy.
  1. Christian Decker, Roger Wattenhofer. "Bitcoin Transaction Malleability and Mt. Gox," Page 2.

  2. Mt. Gox. "Announcement of Commencement of Bankruptcy Proceedings."

  3. Nasdaq. "A $480 Million Mystery: The Saga of Mt. Gox."

  4. CoinDesk. "Mt. Gox Temporarily Suspends USD Withdrawals."

  5. Govinfo.gov. "The Present and Future Impact of Virtual Currency."

  6. CryptoCurrency.org. "The Biggest Exchange Hacks in Cryptocurrency History - Part1: Mt. Gox."

  7. CoinDesk. "Mt. Gox Halts All Bitcoin Withdrawals, Price Drop Follows."

  8. Christian Decker, Roger Wattenhofer. "Bitcoin Transaction Malleability and Mt. Gox," Page 12.

  9. Mt. Gox. "Notice of Confirmation Order of Rehabilitation Plan Becoming Final and Binding."

  10. National Conference of State Legislatures. "The Emergence of Bitcoin."

  11. American Bankruptcy Institute. "Bankrupt Bitcoin Exchange Mt. Gox begins to Pay Back Account Holders in Bitcoin."

  12. Coindesk. "Mt. Gox Deadline Extended Again After Creditors Criticize Refund Proposal."

  13. United States Attorney's Office Northern District of Columbia. "Russian National And Bitcoin Exchange Charged In 21-Count Indictment For Operating Alleged International Money Laundering Scheme And Allegedly Laundering Funds From Hack Of Mt. Gox."

  14. U.S. District Court for the Western District of Washington. "Coinlab, Inc. a Delaware Corporation vs. Mt. Gox KK, a Japanese Corporation and Tibanne KK, a Japanese Corporation."

  15. The United States Department of Justice. "Department of Justice. Journal of Federal Law and Practice. Volume 69, Number 3," Page 200.

  16. Mt. Gox. "Order to Refer Draft Rehabilitation Plan to Resolution."

Take the Next Step to Invest
The offers that appear in this table are from partnerships from which Investopedia receives compensation. This compensation may impact how and where listings appear. Investopedia does not include all offers available in the marketplace.