Bitcoin Could Be 'Taken Down For Just $6 Billion?

A new study suggests that Bitcoin could be destroyed for just $6 billion, as its risk from the “51% attack” could be severely underestimated.

Duke University finance professor Campbell Harvey warned in a new study that the threat of a “51% attack” on Bitcoin is far greater than most investors realize. Although both Bitcoin and gold are viewed as hedges against currency depreciation, Harvey argued that Bitcoin carries far higher systemic risk.

According to his research, an attacker could take control of the Bitcoin network by purchasing roughly $4.6 billion worth of mining hardware, investing another $1.34 billion to build data centers, and spending around $130 million per week on electricity—enough to dominate the network within a single week.

By shorting Bitcoin in the derivatives market, attackers could profit massively from a price collapse, easily covering their costs of the attack. Harvey emphasized: “You can destroy Bitcoin’s value with $6 billion. It sounds highly technical, but it’s way more credible.”

However, Matt Prusak, president of U.S. Bitcoin Corp, dismissed the concerns as exaggerated, noting that accumulating and deploying such vast mining capacity would take years. He added that short positions require enormous collateral and that exchanges could suspend suspicious trading activity.

The 51% Attack: A Fundamental Threat to Bitcoin

A 51% attack occurs when a single entity controls more than half of a blockchain network’s total computing power. Once achieved, the attacker can alter transaction records, reverse payments, and even execute “double-spending” attacks, effectively spending the same digital token twice. Gold, by contrast, faces no such systemic vulnerability.

The booming Bitcoin derivatives market has, according to Harvey, made such attacks more economically feasible. His paper suggests that traders could establish short positions using less than 10% of Bitcoin’s daily trading volume, generating profits large enough to offset the entire cost of an attack.

This potential for outsized profit greatly increases the economic viability of a 51% attack—especially considering that the estimated cost represents just 0.26% of Bitcoin’s total network value, far lower than many investors would expect.

“The low cost of an attack is a serious issue for Bitcoin’s future viability and security. Gold faces no equivalent risk.” Harvey warned.

He also noted that such attacks would most likely be carried out outside the United States, where market manipulation safeguards are weaker.

Industry Divided on the Real Risk

Despite Harvey’s stark warning, opinions within the crypto industry remain split.

Prusak argued that the economic and logistical hurdles make a 51% attack unrealistic in practice. He believes it would take years to accumulate and deploy enough mining equipment—this simply isn’t feasible in the real world.

He also pointed out that shorting Bitcoin requires significant collateral and that exchanges could halt trading if they detect potential manipulation, preventing attackers from realizing profits.

While smaller blockchains have fallen victim to such attacks—Bitcoin Gold and Ethereum Classic, for example—those networks have far lower hash rates and weaker miner support, making them much easier to manipulate than Bitcoin.

In summary, Harvey’s research reignites debate over Bitcoin’s long-term resilience. While many dismiss the $6 billion attack scenario as theoretical, the paper highlights an uncomfortable truth: Bitcoin’s perceived invincibility may rest on far shakier ground than investors assume.