What is the biggest crypto hack ever?

The biggest crypto hack ever, measured in dollars at the time of the theft, is the roughly $1.5 billion taken from the exchange Bybit in February 2025. The list below covers the largest cases with their dates and amounts. For how these attacks work in general, see how crypto gets hacked.

What happened in the Bybit hack?

On or about February 21, 2025, about $1.5 billion in virtual assets was stolen from Bybit, a large exchange. Five days later, the FBI said North Korea was responsible and named the activity "TraderTraitor." It published Ethereum addresses tied to the laundering and asked exchanges, bridges and other services to block transactions from them.

What were the Ronin and Poly Network hacks?

Ronin, March 2022. Ronin is a network built for the blockchain game Axie Infinity. It approved withdrawals when five of nine validators signed. Attackers gained control of five of those keys and approved fake withdrawals of about 173,600 ether and 25.5 million USDC. The theft took place on March 23 and was discovered six days later. In April 2022, the FBI said North Korea-linked groups known as Lazarus and APT38 were responsible for the $620 million theft.

Poly Network, August 2021. On August 10, 2021, an attacker took about $611 million from Poly Network, a service that moves assets across several blockchains. In an unusual twist, the attacker returned nearly all of it within days.

What was the Mt. Gox hack?

Mt. Gox was once the largest bitcoin exchange. It suffered a series of hacks from September 2011 to May 2014, losing roughly 850,000 bitcoin belonging to customers and the company, and went into bankruptcy and liquidation in 2014. Because bitcoin's price has changed so much, its dollar size depends on which date is used, so rankings treat it differently.

What are the other biggest crypto hacks?

• Coincheck, January 2018. The Japanese exchange lost NEM tokens worth about 58 billion yen, around $530 million. They were held in an internet-connected hot wallet without multi-signature protection.
• DMM Bitcoin, May 2024. About 4,502.9 bitcoin, worth around $308 million, was taken from the Japanese company. The FBI attributed it to North Korea's TraderTraitor in December 2024.

Smaller thefts are far more common. The security firm Blockaid counted 212 exploits and more than $1.1 billion stolen in the first half of 2026. The largest single incident in that period, at KelpDAO, was about $292 million.

Recovery is the exception. Stolen funds are hard to claw back, though they can often be traced on public ledgers.

Figures are as reported at the time and may be revised. Check official statements from law enforcement or the affected companies for the latest details.