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Arbitrum

Overview
Status
Mainnet
Type
Alt. Rollup
Fee Token
ETH
BTC Supply
₿0
Arbitrum is an Ethereum rollup that supports a variety of wrapped BTC tokens.
CUSTODY
DATA AVAILABILITY
OPERATORS
FINALITY ASSURANCE
BTC Supply
Total supply per day
Supplycoming soon

TVL Data Coming Soon

We're currently gathering and building data infrastructure for this network. TVL analytics will be available soon.

Token Contracts

Token Contracts Coming Soon

We're working to collect the various BTC-backed token contracts for this network. Contract addresses will be available soon.

Risk Summary
All BTC pegs have custodian trust assumptions
All BTC backing wrapped tokens on this network are ultimately secured by custodians. Users trust that these custodians will not misappropriate funds and keep their assets pegged 1:1. Each custodian has their own risks. Learn more in the trust assumptions review section.
Some contracts immediately upgradeable by Arbitrum Security council
If the security council is compromised, they can immediately upgrade specific contracts and potentially steal user funds. This risk may be relevant to BTC-backed tokens locked in the layer's official bridge contract. The Arbitrum Security council is a 9/12 multisig.
Another network is used for data availability
Data related to the network's state is made available by another consensus network. The network's state cannot make progress if the data availability layer withholds the data. If the network cannot make progress, user funds can be frozen.
A centralized entity is the network operator
The network is operated by a centralized operator. If this operator goes offline, the network can be halted which can freeze user funds. Please see the trust assumptions to learn if their is a fallback mechanism for liveness failures.
Trust Assumption Review
BTC Custody
High
🚨
BTC backing this asset is secured by a federation
tBTC's peg with bitcoin is managed by the Threshold Network, a distributed but permissioned two-way peg. This group of signers participate in a threshold signature scheme to secure the BTC that backs tBTC.

This bridge is managed by a 9 member federation. Bitcoin users trust that 6 of the 9 members of this federation do not collude and steal user funds.
Data Availability
Medium
⚠️
Data is stored and made available by Ethereum full nodes
The data for network's state is made available by Ethereum full nodes. Anyone can run an Ethereum node and verify the state of the network.
Network Operators
Medium
⚠️
Arbitrum blocks are produced and proposed by a centralized operator, but users can propose their own state updates in the event of censorship or liveness failures
The network's sequencer is managed by one entity. The sequencer can censor transactions and can also cause liveness failures if it goes down. Users can bypass the sequencer and send their transactions directly to its parent chain. Users can also self-propose their own state transition, and exit the network to its parent chain.
Finality Guarantees
Medium
⚠️
Arbitrum state transitions finalize by updating its state based on data posted to Ethereum
The network's state is updated offchain by nodes who apply state transition logic over the data made available by its data availability layer. After a new state is generated, a state root may be posted to bridge programs.
Bitcoin Security
Arbitrum does not inherit any security from Bitcoin
In its current state, the network does not inherit security from Bitcoin.
ETH token used to pay fees
Fees to network operators are paid in an alternative token.
No MEV introduced to Bitcoin
The network does not introduce any MEV on the Bitcoin L1. Users trust the sequencer to not reorder their transactions to extract MEV.
Arbitrum does not contribute to the security budget
The network does not currently contribute to the Bitcoin security budget.
Technology
EVM-Compatible
The network uses an EVM-compatible virtual machine. The Ethereum Virtual Machine is software responsible for smart contract execution for a number of blockchains, namely the Ethereum Network. It uses Solidity/Vyper as its code and is the dominant environment for smart contract execution in the cryptocurrency ecosystem.
Fault Proofs (a.k.a Fraud Proofs)
The network leverages cryptographic proofs that enables challengers to contest a proposed state transition that contains invalid or fraudulent transactions. Networks that use fault proofs (e.g., optimistic rollups) initially assume that new blocks are valid, then rely on users or watchtowers to challenge blocks if they include invalid state transitions, which are then resolved onchain or a parent blockchain. Fault proofs are largely used to secure bridge programs securing user funds.
Arbitrum Stylus
In addition to being EVM-compatible, the network leverages Stylus to support developers building WASM-based smart contracts. Developers can decide between building EVM-based applications or writing smart contracts in more common programming languages, such as Rust, and compiling these contracts to WASM.
Use Cases
Onchain applications
Onchain applications are supported. Onchain applications include borrowing and lending protocols, onchain exchanges (commonly referred to as decentralized exchanges), and more. These applications are supported with more expressive smart contract environments.
Knowledge Bits
This network is a layer 2 for Ethereum. For a view into the technology from an Ethereum perspective, head to L2Beat for their review.