Expert: Bitcoin Faces $8B Attack Risk, Ethereum More Secure

Some observers argue that the biggest concern may not be profit, but whether a state-backed attacker would accept losses to damage Bitcoin.

A Duke University finance professor, Campbell Harvey, has said that a 51% attack on Bitcoin, long dismissed as a theoretical exercise that would only destroy value for whoever tried it, has quietly become something an attacker could profit from because of today’s derivatives markets.

However, many BTC supporters dismissed the claim made during the July 12 episode of Scott Melker’s Wolf of All Streets podcast, arguing that it ignores the practical economic barriers that would likely stop such an attack.

Derivatives Have Changed Bitcoin’s Risk Profile

According to Harvey, a 51% attack, where a single entity gains the majority control of the Bitcoin network’s hash power, has always been technically possible but made little economic sense. This is because an attacker would need to spend billions of dollars on mining hardware but would only end up destroying the value of the asset they had just compromised.

“Why would you spend billions investing in mining equipment, take over the network, but the price of Bitcoin collapses to zero?” Harvey posited. “So you spend all that money and get nothing?”

But now, he believes that equation has changed, given that derivative markets carry enough liquidity for an attacker to short BTC before launching an attack and profit as the price falls.

“The difference today is the derivatives markets,” he told Melker. “What you want to do is simultaneously during the attack take a short position on Bitcoin, and with a short the ideal outcome is if the asset goes to zero.”

The professor did point out that the trade would have to take place on offshore derivatives platforms since it amounted to blatant market manipulation. In his research paper titled “Gold and Bitcoin,” he estimated that such an operation would cost about $8 billion, which is roughly 50 basis points of BTC’s total market value, although he framed the scenario as a risk management exercise and not a prediction, arguing that investors should consider every credible threat instead of dismissing uncomfortable possibilities.

When asked the same question, Grok estimated that anyone looking to carry out such an attack would need to spend more than $10 billion on mining machines and about $1.3 million in electricity costs every hour. It also noted that any attempt would most likely be detected immediately.

Interestingly, Harvey does not think the same scenario can work on Ethereum. According to him, since Ethereum switched to proof-of-stake, an attacker has to acquire more than half of the liquid ETH supply to control one-third of all staked Ether, which would rapidly drive prices higher during the attempt and eliminate the short-selling opportunity he described for Bitcoin.

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The educator’s criticism of Bitcoin went beyond its network security, as he argued that the OG cryptocurrency is too volatile to qualify as a safe haven asset or reliable store of value. He said that price swings have stayed high even after years of market growth and deeper liquidity. At the time of writing, BTC was trading near $62,000 after slipping to near $61,000 last week following the renewal of hostilities between the US and Iran.

Bitcoin Community Pushes Back

The response on X to Harvey’s interview was mostly dismissive, with market watcher David Levenson calling the professor’s take “a fundamental misunderstanding of how derivatives work.” Another listener, PrivateCoSaylor, argued that Bitcoin’s social consensus could reject blocks produced by an attacker, making the strategy economically self-defeating.

However, there were those who aired different concerns, including pseudonymous trader Toni, who noted that while the whole argument rested on profit being the motive, the same wouldn’t hold if a nation-state or short seller simply wanted Bitcoin to fail regardless of any losses they incurred.