Circle has launched the public mainnet of Arc, a new Layer-1 blockchain that extends the company's role beyond stablecoins into payments, tokenized assets, foreign exchange, and broader financial market infrastructure. For Circle, the issuer of USDC, the launch marks a shift from building on existing blockchains to operating the underlying infrastructure itself.

The network is designed to support real-time movement of money and financial applications, with USDC serving as the native currency for transaction fees. Arc is also compatible with the Ethereum Virtual Machine (EVM), allowing developers to deploy and operate compatible applications on the network — and letting teams already building for Ethereum port existing tooling and contracts to Arc with minimal rework.

Deterministic Sub-Second Finality

A defining feature of Arc is deterministic sub-second finality, which is intended to allow transactions to reach final settlement rapidly. In payment and settlement contexts, that finality is a practical requirement: once a transaction is deterministically final, it cannot be reversed, which is the condition institutions generally need before treating a transfer as settled. Circle is initially operating the blockchain with a permissioned group of institutional validators as it gradually expands participation.

According to Circle, more than 100 applications and over 100 institutional and ecosystem builders are participating at the mainnet launch. The company said Arc's testnet processed more than 700 million transactions before the public network went live.

Circle Chief Executive Jeremy Allaire described the launch as a major milestone in the company's history, positioning Arc as a broader step toward internet-based financial infrastructure following the development of USDC.

Arc is designed to provide a blockchain infrastructure layer for payments, foreign exchange, lending, trading, and tokenized financial assets, extending Circle's financial ecosystem beyond its stablecoin business.

Several major decentralized finance protocols are live on Arc, including Aave, Morpho, and Uniswap. Their presence is intended to give developers and financial institutions access to established liquidity and financial services from the start of the network's public operation.

Payments and Tokenized Assets Anchor the Network

Circle Payments Network and StableFX are directly connected to Arc. StableFX is designed to facilitate continuous foreign exchange trading and settlement using multiple stablecoins, including USDC, EURC, JPYC, and KRW1.

Tokenized investment products form another component of Arc's initial financial infrastructure. BlackRock's BUIDL and Circle's USYC can be used in activities involving trading, lending, and collateral, potentially expanding the ways tokenized funds can interact with blockchain-based financial markets.

BlackRock's digital assets chief Robbie Mitchnick said purpose-built blockchains could contribute to wider adoption of digital assets. He also indicated that Arc could support stablecoin and payment applications at scale.

Circle announced the launch on X:

Arc Mainnet is live. Built for programmable money, global markets, and agentic economic activity, Arc brings stablecoin-native infrastructure to builders and institutions from day one. Explore what's live on Arc: pic.twitter.com/KzWq7sM8Bg
— Circle (@circle) September 16, 2026

The combination of payment infrastructure, foreign exchange settlement, decentralized finance applications, and tokenized funds reflects Circle's effort to create a blockchain specifically oriented toward financial activity rather than general-purpose transactions alone.

Institutional Validators and a Planned Proof-of-Stake Transition

Arc currently relies on institutional validators, with participation being introduced through a phased process. Circle BlackRock, DTCC, ICE, Mastercard, Visa, and Standard Chartered among the founding validator group — a roster spanning asset management, market infrastructure, payment networks, and banking.

Arc Mainnet is live. Arc launches as the Economic OS for the internet: an open platform for global markets, real-time value movement, tokenized assets, and agentic economic activity. Arc is more than a blockchain. It launches as a full-stack financial platform with assets,… pic.twitter.com/SWg0NlUijO
— Arc (@arc) September 16, 2026

The company has also minted an initial supply of 10 billion ARC tokens. However, Circle has emphasized that the token minting does not represent confirmation of a public launch of ARC as a tradable asset.

Circle plans to transition Arc toward a proof-of-stake model in 2027, under which ARC could eventually support network security, governance, and other coordination functions. Despite the potential transition, USDC is expected to remain Arc's gas currency, meaning users would continue to use USDC to pay transaction fees on the network.

Circle is also developing additional infrastructure for Arc, including payment and tokenized financial-market applications. The company is working on privacy-focused tools and AgentVM, which is intended to expand the network's capabilities for automated economic activity.

The mainnet launch marks a significant expansion of Circle's blockchain strategy, placing Arc alongside its existing stablecoin and payments infrastructure. By combining fast settlement, EVM compatibility, institutional validation, and financial applications, the company is positioning Arc as infrastructure for a wider range of digital financial transactions. The milestones to watch from here are the ones Circle has already scheduled: the phased widening of the validator set beyond its institutional founding group, the planned 2027 move to proof-of-stake, and the delivery of the privacy tools and AgentVM now in development.

Source: CoinTrust