Arbitrum One by Offchain Labs: status and timeline

Arbitrum One

Arbitrum One is the largest optimistic rollup on Ethereum, settling transactions on the L1 while maintaining security via permissionless fraud proofs.

DeployStage 4 of 5

Mainnet active since August 2021. BoLD live. 7,000+ RWA assets. Robinhood Chain generates $3.75M daily fees.

Updated 3 Sep 2026Checked 10 Oct0 updates this week

Milestones

Next · Robinhood Chain (Orbit) processes $3.75M in daily fees

Arbitrum One mainnet launch31 Aug 2021Complete.
Stylus announced2023Complete.
Stylus deployed to mainnet3 Sep 2024Complete.
BoLD governance approval and deploymentFeb 2025Complete.
RWA ecosystem reaches $1 billion TVLSep 2026Complete.
Robinhood Chain (Orbit) processes $3.75M in daily feesTarget 1 Sep 2026Current milestone.

Most important updates

Arbitrum reaches $1 billion in real-world assets TVL3 Sep 2026
BoLD permissionless fraud proofs go live on Arbitrum OneFeb 2025
Arbitrum Stylus mainnet upgrade ships, enabling WebAssembly smart contracts3 Sep 2024
Arbitrum One mainnet launches, opening to all users31 Aug 2021

Upcoming

1 Sep 2026Robinhood Chain (Orbit) processes $3.75M in daily fees (next)
Q4 2026Stylus adoption by major DEX and gaming platforms
2027Shared sequencing rollout (Espresso Systems or partner)

Current obstacles

Sequencer livenessSingle sequencer; users can post to L1 after timeout but pay L1 gas costs.
Fraud proof complexityBoLD is correct but complex; full implementation and bug testing across all chains is ongoing.

Physics limits

Settlement security tied to Ethereum L1Arbitrum's security depends on Ethereum's finality and liveness. If Ethereum suffers a consensus failure, Arbitrum is affected.
Dispute latencyBoLD has a 7-day upper bound for dispute resolution to prevent delay attacks, meaning fund withdrawals during disputes can take a week.

How it works

3 parts

Batching

Compress and batch transactions

Arbitrum One batches user transactions into Nitro batches that are sent to Ethereum L1 as calldata. This amortizes L1 costs across many users.

Fraud Proofs

BoLD dispute resolution

If a proposed state root is wrong, any node can submit a fraud proof challenging it. BoLD uses interactive game theory to isolate the disagreement.

Stylus

WebAssembly execution

Stylus lets developers deploy smart contracts written in Rust, C, or C++, compiled to WASM. These run 10-100x faster and cheaper than Solidity.

Spec sheet

Spec	Arbitrum One
Total Value Locked	$6B+^R (reported)
Real-world assets TVL	$1B+^R (reported)
Tokenized RWA count	7,000+^R (reported)
Settlement layer	Ethereum L1^R (reported)

^R reported by the company

Update log

4 updates

About Offchain Labs

The team behind Arbitrum One

Offchain Labs

Arbitrum rollup, Nitro, BoLD fraud proofs, Stylus, Orbit

Offchain Labs builds Arbitrum, the largest optimistic rollup ecosystem on Ethereum. The company develops the Nitro technology stack, which powers Arbitrum One, Arbitrum Nova, and Arbitrum Orbit chains. Its permissionless BoLD fraud proofs enable decentralized validation.

Arbitrum One is the largest optimistic rollup, supporting over 7,000 tokenized real-world assets with $1B+ TVL in RWAs alone.
BoLD, the permissionless fraud proof system, went live in early 2025, enabling any node operator to challenge invalid state roots.
Arbitrum Stylus, launched in 2024, lets developers write smart contracts in Rust, C, and C++ via WebAssembly, expanding beyond Solidity.

offchainlabs.com (opens offchainlabs.com)Company profile →

Founded: 20188 yrs
Headquarters: United States
Status: Private
Valuation: private
Raised: $120M2 rounds
Last round: Series B · $100MAug 2021
Works in: CryptoRollups & ZK proofs
Coverage: 2 programs · 5 updateslatest 3 Sep 2026checked 10 Oct
Lead investors: Lightspeed Venture PartnersNot specified in source
Customers: Robinhood (opens robinhood.com)Uniswap Labs (opens uniswap.org)
Partners: Ethereum Foundation (opens ethereum.org)
People: Steven Goldfeder (opens linkedin.com)Co-founder & CEOEd Felten (opens cs.princeton.edu)Co-founder & Chief ScientistHarry Kalodner (opens offchainlabs.com)Co-founder & CTO

Spec

Arbitrum One

Total Value Locked

$6B+^R (reported)

Real-world assets TVL

$1B+^R (reported)

Tokenized RWA count

7,000+^R (reported)

Settlement layer

Ethereum L1^R (reported)

Arbitrum One

Milestones

Most important updates

Upcoming

Current obstacles

Physics limits

How it works

Compress and batch transactions

BoLD dispute resolution

WebAssembly execution

Spec sheet

Update log

Thu 3 Sep

Feb 2025

Tue 3 Sep 2024

Tue 31 Aug 2021

About Offchain Labs

Current obstacles

Physics limits

How it works

Compress and batch transactions

BoLD dispute resolution

WebAssembly execution

Spec sheet

Update log

Thu 3 Sep

Feb 2025

Tue 3 Sep 2024

Tue 31 Aug 2021

About Offchain Labs