Unpacking Blockchain Decentralization: ARK Invest & Glassnode Reveal Key Findings for Bitcoin, Ethereum, and Solana

A groundbreaking joint research report from ARK Invest and leading on-chain data analytics firm Glassnode has shed new light on the decentralization of major cryptocurrencies. The study reveals that, when assessing the concentration of block production rights, both Bitcoin and Ethereum require the cooperation of just three primary entities to cross their critical consensus thresholds. In stark contrast, Solana demonstrates a broader distribution, requiring 19 validator entities to reach a similar threshold.

The Nakamoto Coefficient: A Metric for Decentralization

Titled “The Decentralization Spectrum: Design Tradeoffs in Digital Assets,” the report employs the Nakamoto Coefficient as a key metric. This coefficient quantifies the minimum number of independent entities that would need to collude to gain sufficient control (hash rate or staking weight) to disrupt a network’s operations. For Bitcoin, the critical threshold is set at 51% of the network’s hash rate. For Proof-of-Stake (PoS) networks like Ethereum and Solana, the threshold is 33% of the total staking weight, reflecting the active risk of preventing network finality.

Key Findings: Bitcoin, Ethereum, and Solana Compared

The report’s analysis, based on a July 2026 data snapshot, offers specific insights into each blockchain:

Bitcoin’s Nakamoto Coefficient: 3

The study found that Foundry USA controlled 27.27% of Bitcoin’s mining pool hash rate. When combined with AntPool (17.06%) and F2Pool (16.96%), these three entities collectively commanded approximately 61.29% of the network’s hash rate. This figure comfortably surpasses the 51% threshold, leading to a Nakamoto Coefficient of 3 for Bitcoin.

Ethereum’s Nakamoto Coefficient: 3

For Ethereum, the concentration of staked ETH shows a similar pattern. Lido accounted for 23.04% of staked ETH, with Binance and Kraken holding 8.88% and 6.91% respectively. The combined stake from these three entities reached approximately 38.83%, exceeding the 33% threshold. Consequently, Ethereum’s Nakamoto Coefficient was also determined to be 3.

Solana’s Nakamoto Coefficient: 19

Solana presented a different picture. Its largest validator, Figment, held only 3.78% of the delegated stake. To reach the 33% threshold required to disrupt finality, the report indicates that the top 19 ranked validators would need to collude. This significantly higher number suggests a more distributed validator landscape compared to Bitcoin and Ethereum in this specific metric.

Nuance and Context: Beyond the Numbers

It is crucial to interpret these findings with nuance. The report explicitly cautions against a simplistic interpretation that merely three entities could “take over” Bitcoin or Ethereum:

• Bitcoin’s Mining Pools: The statistics for Bitcoin refer to mining pool hash rate, not direct ownership of mining hardware. Individual miners can readily switch their hash rate to different pools. While pools can influence block templates, transaction inclusion, and ordering, this does not equate to ownership of the underlying mining machines or the Bitcoin held by individual miners.
• Ethereum’s Lido: Lido is a liquid staking protocol that aggregates stake across numerous independent node operators, rather than being a single, monolithic validator. While exceeding one-third of staking weight can hinder finality, a substantially higher proportion would be necessary to consistently dictate chain fork choices or self-finalize preferred blocks.

The Decentralization Spectrum: Trade-offs and Complexities

The report also delivers an important warning: the 51% hash rate threshold for Bitcoin (Proof-of-Work) is fundamentally different from the 33% staking weight threshold for Proof-of-Stake networks. Therefore, a direct “3 versus 19” comparison cannot unilaterally declare Solana as more decentralized overall than Bitcoin or Ethereum.

Glassnode emphasizes that each of the three chains exhibits unique trade-offs across various dimensions of decentralization:

• Bitcoin: Demonstrates greater strength in independent validation, ownership distribution, and geographical resilience.
• Solana: Achieves a higher Nakamoto Coefficient in terms of validator stake distribution but also shows a higher reliance on specific node hardware and centralized data centers.

Ultimately, the study underscores that decentralization is a multi-faceted concept, and different blockchain designs prioritize different aspects. Understanding these design trade-offs is essential for a comprehensive assessment of network robustness and security.