Cryptocurrency Hacks: The Bitter Moments in the History of Cryptocurrencies

The Coin Times
5 min readNov 21, 2021


In October 2021, Bitcoin reached a new all-time high of $66,100. As things stand, everyone who has ever bought Bitcoin will make a profit. While venturing into the cryptocurrency space may hold the promise of bountiful returns, there remain several ugly moments in history that suggest that this is not always the case.

In early 2021, DeFi aggregator Yearn Finance lost about $2.7 million to a flash loan attack:

Top cryptocurrency exchanges and protocols have had cases of thefts from hacks in which investors’ funds were stolen over the years. Rug pulls, honeypots and outright scams are now a common occurrence, and the loser in all these events is the ordinary investor. There are more incidents of such nature in the crypto space today, affecting a larger number of people than in the past.

Here are some of the biggest cryptocurrency hacks in history:

Mt. Gox

The Mt. Gox incident remains the biggest Bitcoin theft yet, in terms of volume. The exchange began actively overseeing Bitcoin trading in 2010, and remained in operation till 2014. At one time, Mt. Gox handled over 70% of all Bitcoin transactions globally. Sometime in 2014, after countless issues with customers’ deposits and transfers, the exchange reported a hack. 850,000 Bitcoins were lost as a result. Although they recovered 200,000 bitcoins, the total loss amounted to $450 million at that time. Today, it is worth almost $43 billion. Mt. Gox filed for bankruptcy in 2014, leaving customers stranded and at a loss.

Official logo of the Mt. Gox exchange while it remained in operation.


Japanese exchange Coincheck suffered a notable hack in January 2018, which led to the theft of over 523 million NEM coins. NEM is the native token of Coincheck, as BNB is to Binance. The theft was then valued at $534 million and was the largest crypto heist in history at the time. The hackers targeted the hot wallets of the exchange, where cryptocurrencies were stored.


In another major exchange hack, Bitfinex announced the theft of 119,756 Bitcoins from its platform in August 2016. Again, the hackers targeted the hot wallets for the online storage of cryptocurrencies. The total haul was worth some $72 million at the time. Currently, those 119,756 bitcoins are valued at close to $8 billion. The hackers exploited the multi-signature wallets where the exchange kept its crypto. Somehow, they were able to access the keys and drain the wallets.


In May 2019, hackers bypassed Binance’s security system and made away with at least 7,000 Bitcoins. The theft was valued at $40 million at the time but is worth at least ten times that amount today. The hackers withdrew the Bitcoins from the exchange’s hot wallet, and also gained control over some users’ accounts. Binance, however, covered the loss fully, protecting their investors’ funds.

The South African Brothers

Not a hack, but still worth a mention; 2021 brought yet another bitter moment in the history of cryptocurrencies when the founders of Africrypt made away with $3.6 billion worth of Bitcoin. Posing as an investment scheme and crypto bank, the two brothers attracted a large number of investors seeking a good return on their cryptocurrencies. The brothers, Ameer and Raees Cajee, remain at large to this day.

Poly Network

The largest DeFi hack in history happened in 2021 when Poly Network lost over $600 million to hackers. The hackers exploited a bug in Poly Network’s system, and drained different cryptocurrencies, moving them to three wallet addresses. The DeFi platform released a statement appealing to the hackers to return the stolen funds and also urged exchanges to blacklist the tokens. While Tether reported that it had frozen $33 million worth of USDT, a fraction of the stolen funds, the hackers returned close to half of the loot, some $260 million.

Twitter Thefts

Albeit not a direct crypto hack, hackers violated the Twitter accounts of top brands and figures in the world like Apple, Elon Musk, Barack Obama, and Bill Gates. These hackers proceeded to upload a mischievous tweet, asking followers to send Bitcoin to given addresses and receive double of their funds. At least 130 Twitter accounts were compromised, and 45 were used to send the tweets. One of the Bitcoin addresses received over 12 Bitcoins within minutes, and Coinbase blocked Bitcoin transactions, after blacklisting the addresses, to the tune of $280,000. The incident put the entire crypto community in a bad light.

One of the tweets the hackers used Apple’s Twitter account to send.


Another victim of hackers in 2018, BitGrail, an Italian cryptocurrency exchange, lost 17 million NANO tokens after several breaches were reported in February. The tokens were worth $170 million at the time and the majority were investors’ funds. This particular incident remains broiled in controversy, as authorities in Italy believe the exchange’s owner is complicit. Francesco Firano, BitGrail’s founder, made a strange request to the developers to fork the NANO blockchain. The request was however declined, due to suspicions of foul play.


In 2017, crypto-mining marketplace NiceHash suffered a hack leading to the loss of 4,736 bitcoins worth over $300 million today. The company released a statement claiming that the hacker was able to access an employee’s confidential information, and that led to the breach. The NiceHash incident is worth a mention because the company has fully compensated all investors who lost their funds.

DeFi protocols, centralized and decentralized exchanges are targets of hackers seeking to exploit bugs. Invest wisely, and stay SAFU out there.