Experts Warn Over 51% Attack Risk as Bitcoin Mining Centralizes Around Foundry and AntPool

• Two major Bitcoin mining pools control over 51% of the network’s hashrate, raising fears of centralization.
• A 51% attack remains unlikely due to high costs and economic risks, but investor confidence is under pressure.

Bitcoin’s network security faces renewed scrutiny after new data revealed that two major mining pools now control over half of the total mining power. The growth has raised concerns regarding the threat of a 51% attack, which questions the image of the cryptocurrency being a decentralized network.

Analyst Jacob King notes that Foundry has 33.63% of the hashrate of Bitcoin, and AntPool maintains 17.94%. Collectively, they control over 51% of mining power in the network. In the event of such synchronized pools, they might be able to control the network by accepting invalid transactions or even reorganizing legitimate blocks.

The trend has raised concerns among community members who argue that this concentration level is a malpractice against the decentralized spirit that has characterized Bitcoin over the years.

Evan Van Ness shared statistics showing that the top three pools frequently account for more than 80% of global hashrate, reinforcing concerns about a shrinking distribution of mining control.

The current situation marks the first time in more than a decade that Bitcoin’s mining concentration has reached such a level, raising questions about the long-term sustainability of Proof-of-Work (PoW) as Bitcoin’s security model.

Risks of a 51% Attack

A 51% attack would give majority control of the network’s hashrate to one or a few parties, enabling them to block transactions, reverse completed transfers, or execute double-spending. Such actions could destabilize trust in Bitcoin and cause significant financial disruption.

While the technical requirements for executing such an attack remain extremely high, the perception of vulnerability itself can influence investor confidence. Analysts caution that even if no attack occurs, the mere possibility could drive institutions to reconsider Bitcoin’s role as a secure digital asset.

Some experts warn that a successful attack could transform Bitcoin from a decentralized store of value into a perceived liability. Institutional investors, in particular, may hesitate to allocate capital if they view Bitcoin’s infrastructure as fragile or exposed to manipulation.

Economic Barriers and Incentives

Despite the concentration of mining power, industry specialists note that the costs of carrying out a 51% attack are prohibitively high. Such an effort would require massive infrastructure, extensive hardware, and enormous energy consumption. These barriers make an actual attack logistically challenging.

Additionally, miners have a strong economic incentive to protect the network. A 51% attack could cause Bitcoin’s price to collapse, directly harming those who invested in and control the hashrate. This paradox suggests that while mining pools theoretically have the capability, the economic consequences make an attack highly unlikely.

The concentration of mining power reignites debate about the suitability of PoW as Bitcoin’s foundation. While PoW secures the network through computational effort, its reliance on a limited number of industrial-scale mining operations has led to centralization.

Alternatives such as Proof-of-Stake (PoS) are often presented as more resistant to concentration, though Bitcoin has historically resisted protocol changes. Critics argue that Bitcoin’s inability to adapt its consensus model could leave it increasingly vulnerable to systemic risks.