The Biggest Crypto Hacks in History, Ranked by Reported Loss

The largest reported cryptocurrency heist in this group was the roughly $1.5 billion stolen from exchange Bybit in February 2025. The incidents below span exchange wallets, a cross-chain bridge and transaction-approval systems. Their dollar figures are approximate values at the time of the theft, so reports may differ. 2

The five major crypto heists at a glance

Incident	Date	Approximate loss	Target and reported weakness	Outcome
Bybit	February 2025	$1.5 billion	Exchange cold-wallet transfer; compromised transaction-signing process	The FBI attributed the theft to North Korean hackers. Bybit said it covered customer balances; that does not mean the stolen crypto was recovered. 2
Ronin Network	March 2022	$625 million	Bridge used by the Axie Infinity game; attackers obtained enough validator credentials to approve withdrawals	US authorities attributed the attack to North Korea’s Lazarus Group. Some funds were later recovered, and the bridge operator arranged reimbursement. 2
Poly Network	August 2021	$610 million	Cross-chain transaction controls	The attacker returned nearly all the funds; the perpetrator’s identity was not conclusively established in the cited reporting.
Coincheck	January 2018	$530 million	NEM tokens in an internet-connected exchange wallet	Coincheck compensated affected customers; the perpetrators were not conclusively identified in the cited reporting.
Mt. Gox	Disclosed February 2014	$450 million–$500 million	About 850,000 bitcoin went missing amid exchange security and accounting problems	The exchange collapsed. Responsibility for the theft remains contested, and some creditors have received repayments through a lengthy process. 2

How the biggest attacks worked

Bybit: a compromised signing process

On February 21, 2025, attackers stole ether worth about $1.5 billion from Bybit. Reports described a cold-wallet transfer in which the transaction signers were misled about what they were approving. The FBI attributed the theft to North Korean hackers. Bybit said customer balances were covered, but covering customer balances is different from recovering the stolen assets. 2

Ronin Network: validator credentials enabled bridge withdrawals

In March 2022, attackers stole about $625 million from Ronin, a network connected to the Axie Infinity game. The attack used compromised validator credentials to authorize withdrawals from the bridge. US authorities attributed it to North Korea’s Lazarus Group. Some funds were later recovered, and the bridge operator arranged reimbursement. 2

Poly Network: a cross-chain control failure

The August 2021 Poly Network theft involved about $610 million. A weakness in the platform’s cross-chain transaction controls allowed an attacker to redirect assets. The attacker returned nearly all of the funds, an unusual resolution for a theft of this scale.

Coincheck: tokens held in an online wallet

In January 2018, thieves took about $530 million in NEM tokens from Coincheck. The tokens were held in an internet-connected wallet, exposing the exchange’s assets to online attack. Coincheck compensated affected customers; the perpetrators were not conclusively identified in the cited reporting.

Mt. Gox: a long-running loss ended in collapse

Mt. Gox disclosed in February 2014 that about 850,000 bitcoin had gone missing. The bitcoin was valued at roughly $450 million to $500 million at the time. The exchange collapsed, and responsibility for the loss remains disputed. Some creditors have received repayments through a lengthy process. 2

What Bitget and 2025 theft totals add to the picture

In September 2026, Bitget reported unauthorized transfers initially estimated at about $351.6 million and temporarily suspended withdrawals. The company said customer funds were safe and that its own funds would cover the loss. A later report gave a revised estimate of about $387.5 million, so the reported total was not consistent across updates. Bitget’s chief executive said North Korean involvement was suspected; that attribution was not confirmed. 1349

The broader numbers put these individual incidents in context. TRM Labs estimated that illicit actors stole $2.87 billion across nearly 150 hacks in 2025; the Bybit breach accounted for about $1.46 billion, or 51%, of that total.

Authorities have also warned that organized criminal groups use cryptocurrency to move funds quickly across borders, bypassing conventional financial systems. 13 Together, these cases illustrate why crypto security depends on more than protecting private keys: transaction preparation, approval, wallet operations and bridge controls can all become points of failure.