What Is Arbitrum?

Arbitrum is an Ethereum layer-2 scaling solution developed by Offchain Labs, founded by Ed Felten (former White House Deputy CTO), Steven Goldfeder, and Harry Kalodner. Arbitrum One, the main network, launched in August 2021 and grew into the largest Ethereum L2 by total value locked (TVL), a position it held for years until Base overtook it in 2026 as Arbitrum's DeFi deposits fell sharply in the wake of the April 2026 Kelp DAO crisis.

• Overview - Table of Contents
• What Is Arbitrum?
• Getting Started With Arbitrum
• How To Get An Arbitrum Wallet?
• Arbitrum Resources
• How To Buy ARB?
• Latest Arbitrum News

Arbitrum uses optimistic rollup technology to scale Ethereum. Transactions are executed off-chain on Arbitrum's network, and compressed transaction data is posted to Ethereum. The term "optimistic" refers to the assumption that transactions are valid by default. A fraud proof system allows anyone to challenge a transaction during a dispute period if they believe it was processed incorrectly. This design provides Ethereum-level security while dramatically reducing costs and increasing throughput.

Arbitrum achieves strong EVM compatibility through its custom virtual machine called Nitro. Built on a modified version of Geth (Ethereum's main client), Nitro provides near-perfect compatibility with Ethereum, meaning smart contracts can be deployed on Arbitrum with little to no modifications. This has made Arbitrum the easiest L2 for Ethereum projects to expand to, contributing to its large ecosystem.

The ARB token is the governance token of the Arbitrum DAO, which governs the Arbitrum One and Arbitrum Nova networks. ARB holders can vote on proposals that affect the protocol's development, treasury management, and ecosystem growth. The Arbitrum DAO controls a significant treasury funded by the initial ARB token allocation.

Arbitrum hosts a massive DeFi ecosystem. Major protocols include GMX (perpetuals DEX), Uniswap, Aave, Camelot (native DEX), and Pendle (yield trading). Many DeFi protocols have seen their highest activity on Arbitrum, making it a critical part of the Ethereum scaling landscape.

In addition to Arbitrum One, Offchain Labs operates Arbitrum Nova, a separate chain optimized for gaming and social applications with even lower fees using AnyTrust technology. Arbitrum also provides Orbit, a framework for launching custom L3 chains that settle on Arbitrum.

Getting Started With Arbitrum

Getting started with Arbitrum:

1. Step 1: Add the Arbitrum One network to MetaMask or use any EVM-compatible wallet.
2. Step 2: Bridge ETH or tokens from Ethereum using the official Arbitrum Bridge, or withdraw directly to Arbitrum from a supported exchange.
3. Step 3: Use ETH on Arbitrum to pay for gas fees (fees are paid in ETH, not ARB).
4. Step 4: Explore DeFi protocols, trade on DEXs, or interact with other dApps on Arbitrum.

How to Get an Arbitrum Wallet?

MetaMask

MetaMask is the most commonly used wallet for Arbitrum. Add the Arbitrum One network through Chainlist or the Arbitrum bridge to get started. Since Arbitrum is EVM-compatible, MetaMask works seamlessly.

Rabby Wallet

Rabby is a browser extension wallet with native support for Arbitrum and many other EVM chains. It automatically detects which network a dApp is using and provides a clean multi-chain experience.

Hardware Wallets

Ledger and Trezor hardware wallets work with Arbitrum through MetaMask, providing secure offline key storage for your Arbitrum assets.

Arbitrum Resources

• Arbitrum Official Website
• Offchain Labs GitHub
• Arbitrum Documentation
• Arbiscan Block Explorer
• Arbitrum Blog
• Arbitrum on X
• Arbitrum Reddit
• Arbitrum Discord
• Arbitrum Telegram

How to Buy ARB?

ARB is widely available on cryptocurrency exchanges:

Centralized Exchanges

ARB can be purchased on Coinbase, Binance, Kraken, and most major exchanges. Trading pairs include ARB/USDT, ARB/USD, and ARB/BTC.

Decentralized Exchanges

On Arbitrum, Camelot, Uniswap, and SushiSwap are popular DEXs for trading ARB and other tokens. On Ethereum mainnet, ARB can be traded on Uniswap.

Note: Gas fees on Arbitrum are paid in ETH, not ARB. You will need ETH on Arbitrum to interact with dApps.

Latest Arbitrum News

In January 2026, Arbitrum activated the ArbOS 51 "Dia" upgrade. In April 2026, after the roughly $292 million Kelp DAO rsETH exploit, the Arbitrum Security Council froze 30,766 ETH (about $71 million) in exploit-linked funds on the network, an unprecedented intervention that sparked intense debate about how decentralized the network really is. In May 2026, the Arbitrum DAO voted overwhelmingly to release the funds for recovery, and a US judge modified an earlier freeze order to expressly permit the transfer.

Elsewhere in the ecosystem, the Arbitrum-based perpetuals platform Ostium was exploited for roughly $24 million on July 15, 2026. On the governance side, a proposal to introduce stARB staking for the ARB token received preliminary approval, and Arbitrum Orbit chains continue to expand the network's reach. One long-standing lending protocol, Radiant Capital, began winding down in June 2026 after failing to recover from a $50 million hack.