Arbitrum

What is Arbitrum (ARB)?

Arbitrum is a suite of Ethereum scaling technologies built by Offchain Labs. Its main network, Arbitrum One, is an optimistic rollup: it executes transactions off the Ethereum base layer, posts the transaction data back to Ethereum, and assumes results are correct unless someone proves otherwise. ARB is the governance token of the Arbitrum ecosystem. It was introduced in March 2023, when the Arbitrum DAO was launched and an airdrop was announced for early users.

How Arbitrum works

A sequencer orders transactions and publishes them quickly, then posts compressed batches to Ethereum, which gives the transactions Ethereum-level finality. Validators post claims about the chain's state with a bond. If a claim is disputed, the dispute is narrowed down to a single step that is checked on Ethereum, and the party that was wrong forfeits its bond. Unchallenged claims are confirmed after a challenge period of about 6.4 days, so canonical-bridge withdrawals take about a week. The dispute system, called BoLD, lets anyone take part in validation.

The platform also includes Arbitrum Nova, which uses a data availability committee for lower fees, and Stylus, which lets developers write contracts in Rust, C and other languages that compile to WebAssembly.

What ARB is used for

• Voting on proposals that affect Arbitrum One and Nova, including upgrades and use of DAO treasury funds
• Delegating voting power to another address while keeping the tokens in your own wallet

ARB supply and token design

The initial supply was 10 billion ARB. The DAO can mint new tokens at a rate of no more than 2% of supply per year, and only through a constitutional proposal, so ten billion is the starting supply and not a hard cap. The documented allocation gave roughly 35% to the DAO treasury, about 27% to the team and advisors, about 17.5% to investors, and about 12% to the airdrop. Team and investor tokens are subject to four-year lockups, with unlocks beginning one year after launch and continuing monthly. ARB is an ERC-20 token created on Arbitrum One and bridged to other networks. Live circulating supply is shown in the market data on this page.

Official information is on arbitrum.io.

What to check before using ARB

• Governance power: voting weight follows token holdings, so a large delegate or holder can have outsized influence over proposals.
• Possible dilution: the DAO has the right to mint up to 2% a year, and scheduled team and investor unlocks add tokens to the market over time.
• Value capture: ARB is a governance token and does not pay gas, so its link to network activity is indirect and depends on what the DAO decides.
• Withdrawal delay: moving funds back to Ethereum through the canonical bridge takes about a week, and third-party bridges add their own risk.
• Fake tokens: ARB exists at different addresses on Ethereum, Arbitrum One and Nova, so verify the contract from official documentation before trading.