Arbitrum is the largest Ethereum Layer 2 ecosystem by TVL and developer activity. Built by Offchain Labs using optimistic rollup technology, it hosts the deepest DeFi liquidity outside Ethereum mainnet and has become the default home for sophisticated EVM DeFi.
Arbitrum One vs Arbitrum Nova
Arbitrum One: The primary chain for DeFi. EVM-equivalent, optimistic rollup, inherits Ethereum security. Home to GMX, Camelot, Radiant, Pendle, Dopex, and most major protocols.
Arbitrum Nova: A separate chain using AnyTrust technology instead of full rollup. Data availability is handled by a committee (not published fully to Ethereum), making transactions much cheaper but with slightly weaker security guarantees. Used primarily for gaming and social apps where low cost matters more than maximum security.
The Nitro Upgrade and Stylus
Arbitrum Nitro (2022) rewrote the Arbitrum stack for dramatically lower gas costs and better EVM compatibility. WASM-based fraud proofs replaced the older approach.
Arbitrum Stylus (2024): Lets developers write smart contracts in Rust, C, and C++ that compile to WASM and execute alongside EVM contracts. Performance for compute-heavy contracts (ZK proofs, AI inference, complex math) can be 10–100x more gas efficient than Solidity.
Orbit Chains: Arbitrum's L3 Framework
Arbitrum Orbit lets anyone deploy a custom L3 chain that settles to Arbitrum One or Nova. Key Orbit chains:
- Xai: Gaming L3, high transaction throughput for on-chain games
- Degen Chain: Community chain for the Degen token/Farcaster ecosystem
- Treasure: Gaming and NFT ecosystem L3
Orbit chains share Arbitrum's security stack but can have custom gas tokens, throughput, and governance.
Top DeFi Protocols on Arbitrum
GMX: Largest perp DEX on Arbitrum. BTC/ETH/SOL and synthetic markets with up to 100x leverage.
Camelot: Native Arbitrum DEX with dual-pool architecture (stable + volatile) and ecosystem launchpad. GRAIL token.
Radiant Capital: Cross-chain lending protocol using LayerZero. Deposit on Arbitrum, borrow on BNB Chain, or vice versa.
Pendle Finance: Yield trading for ETH LSTs and RWA yield tokens. Largest Pendle TVL is on Arbitrum.
Jones DAO: Yield vaults with automated options strategies for ETH, BTC, and ARB. Higher-risk/higher-yield approach.
Dopex: Options protocol on Arbitrum. Single Staking Option Vaults (SSOVs) for covered call and put selling strategies.
ARB Token and Governance
ARB is Arbitrum's governance token, distributed in a large airdrop in March 2023 to Arbitrum One and Nova users.
The Arbitrum DAO (governed by ARB holders) controls:
- The Security Council (emergency upgrades)
- Protocol upgrade approvals
- Treasury spending (billions in ARB)
- Grants programs (LTIPP, STIP — liquidity incentive programs)
Arbitrum DAO governance is one of the most active and well-funded in DeFi. STIP (Short-Term Incentive Program) distributed hundreds of millions in ARB to protocols that applied, driving significant TVL growth.
Bridging to Arbitrum
Official bridge (bridge.arbitrum.io): Trustless, uses Ethereum rollup security. Deposits: ~15 minutes. Withdrawals to Ethereum: 7-day challenge period.
Fast bridges (Across, Stargate, Hop): 1–5 minute transfers in both directions. Pay a small fee to skip the 7-day withdrawal window.
For most users: use Across or Stargate for speed. Use the official bridge for trustless large transfers where you can wait.