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Arbitrum

ARB

Ethereum L2 Optimistic Rollup. Centralized sequencer. Security Council multisig can upgrade contracts. Users can force-exit via L1.

Last updated: Jan 12, 2026

2.7
Total Score

0.4 × Chain + 0.4 × Control + 0.2 × Fairness

1.8

Chain Score

Technical and economic decentralization of the chain

3.2

Control Score

Power and control structures around the protocol

3.4

Fairness Score

Launch, distribution, and governance fairness

Notes

  • *SEQUENCER STATUS: Centralized sequencer operated by Arbitrum Foundation. Decentralization roadmap targets Q2 2026.
  • *STAGE 1 (L2Beat): Permissionless fraud proofs enabled via BoLD upgrade. Users can force transactions via L1 with up to 24h delay.
  • *SECURITY COUNCIL: 9/12 multisig can upgrade contracts immediately. Users have forced exit path but cannot prevent upgrades.

Chain Score

Technical/economic decentralization

A1

Nakamoto Coefficient

Number of independent entities that would need to collude to compromise the system. Higher is better.

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1.3
A2

Validator/Miner Concentration

Share of top 5 validators/miners in stake/hashrate. Lower concentration is better.

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1.0
A3

Client Independence

Number of independently developed full-node implementations. Measures resilience against single-codebase bugs and single-entity control.

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3.0
A4

Node Geography & Hosting

Geographic distribution of nodes and cloud hosting concentration. Lower cloud % is better.

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N/A
A5

Full Node Decentralization

Number of independent full nodes validating the chain. More nodes = harder to attack, better censorship resistance. For PoW chains, this is separate from miners. For PoS, validators often = nodes.

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N/A

Control Score

Power and control structures

B1

Corporate/Foundation Capture

Is there a dominant company/foundation controlling roadmap, marketing, and hiring? Can the project survive without them?

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2.8
B2

Repo/Protocol Ownership

Distribution of merge rights in core repositories (clients, specs). More distributed is better.

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3.4
B3

Brand & Frontend Control

Who owns brand, domains, main frontends, official wallets/apps? Decentralized ownership is better.

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3.0
B4

Treasury & Upgrade Keys

Composition of treasury/upgrade multisigs and admin keys. More independent signers is better.

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4.0
B5

Admin Halt Capability

Can a single entity or small group unilaterally halt, freeze, or censor the chain? This is a critical centralization risk.

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5.0
B6

Protocol Immutability

Has the protocol made fundamental rule changes (consensus mechanism, monetary policy, contentious forks)? Immutable rules are a core property of decentralization.

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1.0

Fairness Score

Launch and distribution fairness

C1

Launch Fairness / Premine

Team/VC/Foundation premine and launch model (fair launch vs. sale/IDO). Less premine is better.

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3.5
C2

Token Concentration

Share of circulating supply held by insiders (team/VC/foundation). Less concentration is better.

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3.6
C3

Governance Control

Share of governance voting power held by insiders. 100% = no token governance (team decides everything). Less insider control is better.

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3.0