Crypto exchange hacks: the biggest thefts and their market effect

Why do crypto exchange hacks hit prices so hard?

An exchange is where most buyers and sellers meet, so a breach there hits price discovery itself. When trading halts, quoted prices on the victim drift away from the rest of the market, and arbitrage needs withdrawals that are frozen. Holders on other venues see the gap and read it as stress. That is the market effect in its simplest form: a local problem becomes a global signal.

The cases below come from public accounts consulted on 23 October 2026. Each one is described by what was stolen, how the venue responded, and what is documented about prices. Where a source states no price move, this page states none either, so every number you read can be traced to a record. This approach also keeps the comparison fair, since each venue faced a different market, a different year, and a different regulator.

What did the Mt. Gox theft do to Bitcoin?

Mt. Gox filed for civil rehabilitation in Tokyo on 28 February 2014. The company first said it had lost almost 750,000 of its customers’ bitcoins plus about 100,000 of its own, roughly 7% of all bitcoins. After it reported finding 199,999.99 BTC on 20 March 2014, the reported loss fell from 850,000 to 650,000 bitcoins.

The market effect is visible in prices. Around 20 February 2014, Mt. Gox’s quoted prices dropped below 20% of the prices on other exchanges, and bitcoin’s value fell 36% from 1 February to the end of March 2014. The venue had handled over 70% of the world’s bitcoin trades, so its failure removed the main place to trade, not a side venue.

How did the 2016 Bitfinex crypto exchange hack affect Bitcoin?

Bitfinex announced its breach in August 2016. The thief took 119,756 bitcoins, valued at about $72 million at the time. The exchange halted all bitcoin withdrawals and trading while it tracked the perpetrators, and its access to US dollar payments and withdrawals was curtailed later.

Bitcoin’s price plunged by 20% right after the breach, which cut the value of the stolen coins to $58 million. Bitfinex reduced the balance of every customer by 36%, including accounts that were not breached, and gave customers BFX tokens in proportion to their losses. US authorities seized a portion of the stolen bitcoin in February 2022, years after the theft.

What did the Coincheck exchange hack show?

In January 2018, about 500 million NEM tokens, valued at $530 million, were stolen from Coincheck in Japan. The exchange halted trading and, after first warning that it might not compensate everyone, said it would repay all 260,000 affected users in Japanese yen from its own capital.

Japan’s Financial Services Agency ordered Coincheck to improve its security practices and did not order the exchange to shut down, citing concern for its users. Coincheck added tighter identity verification, a review of its management system, and stronger internal controls. The case shows a regulator-guided path where customers are made whole and the venue keeps operating.

How did the Bybit theft of 2025 play out?

Bybit announced on 21 February 2025 that about 400,000 Ether had been stolen, a loss described as $1.5 billion in assets. The account consulted ties the breach to compromised infrastructure at Safe{Wallet}, a third party provider, and notes that the FBI blamed North Korea, citing TraderTraitor actors.

Bybit reported that it could replenish its reserves within 72 hours by securing 447,000 Ether through emergency funding, with Galaxy Digital, FalconX, and Wintermute providing liquidity. The outcome differs from Mt. Gox: a very large theft, and a venue that kept honouring withdrawals thanks to outside liquidity.

How do the biggest crypto exchange thefts compare?

Set side by side, the 4 cases differ in size, in speed of response, and in who paid. Mt. Gox ended in bankruptcy, Bitfinex spread the loss across customers at 36%, Coincheck repaid 260,000 users from its own capital, and Bybit restored reserves through emergency funding within 72 hours.

Price effects differ too. Only 2 of the 4 sources report a direct bitcoin move: a 36% fall across February and March 2014, and a 20% plunge after the Bitfinex breach. The others are documented as events without a stated market move. A reader should treat each effect as a documented case, not as a rule.

What can exchange users check before the next theft?

Before the next theft, ask each venue 4 questions. Does it publish audited reserves? How does it separate customer funds from its own? What is its stated plan if a breach occurs? Who covers a loss? Write the answers down with their dates. A venue that answers clearly gives you information, and a venue that answers vaguely gives you a signal too. Repeat the review every quarter, because custody arrangements, partners, and reserves change, and a venue that scored well last year may hold a different risk profile today.

Teams in Singapore, ASEAN, and Hong Kong can add these answers to a counterparty review. A 30-minute pre-diagnostic with EQOS Asia scores your own case, and the Λ simulator lets you test a first version yourself. This page is general information, not investment advice.

Frequently asked questions

About the author

Stéphane Jambu

President, EQOS Forecast Asia

Stéphane Jambu leads EQOS Forecast Asia and works as a consultant in e-commerce, search visibility, and AI. LinkedIn profile