Circle launches Arc blockchain mainnet with BlackRock, Visa, and Mastercard as validators

Circle has launched its Layer 1 Arc blockchain mainnet, securing a historic validator cohort of financial giants including BlackRock, Visa, Mastercard, and DTCC. Operating under a permissioned proof-of-authority model, Arc delivers sub-second deterministic finality with gas fees paid in USDC. Circle also completed a genesis mint of 10 billion ARC tokens, though it has not committed to a public sale. The network launches with over 100 applications, including integrations with Aave, Uniswap, and BlackRock's BUIDL fund.

Arc mainnet launch

• ▪Circle's Arc testnet, which launched in October 2025, processed more than 700 million transactions in less than a year prior to the mainnet launch.
• ▪Circle launched the public mainnet of its Layer 1 blockchain, Arc, on Wednesday, September 16, 2026.
• ▪The Arc mainnet went live with more than 100 applications and over 100 institutional and ecosystem partners participating from day one.

Permissioned validator architecture

• ▪Arc's permissioned validator model is designed to provide a defined governance perimeter that allows banks to use a public chain for treasury, trading, and confidential payments.
• ▪Arc operates under proof-of-authority rules at launch with a permissioned validator set, with plans to explore a transition to a permissioned proof-of-stake model in 2027.

Institutional validator cohort

• ▪Circle and DTCC plan to collaborate to enable the tokenization of DTC-custodied assets on Arc, with the initiative expected to launch in the second half of 2027.
• ▪Arc's founding validator cohort includes BlackRock, DTCC, Mastercard, Visa, ICE, Standard Chartered, SBI Group, Sumitomo Corporation, Galaxy, MoneyGram, and Worldpay (now Global Payments).

ARC token genesis mint

• ▪Circle previously raised $222 million in a private Arc token presale at a $3 billion fully diluted network valuation, which was completed on May 11, 2026.
• ▪Circle stated that the genesis mint of 10 billion ARC tokens is a technical milestone and does not represent a commitment to publicly launch or sell the token.
• ▪Circle minted the entire opening supply of 10 billion ARC tokens in the United States during the week of September 14, 2026.

Technical specifications

• ▪Arc supports optional post-quantum signatures at launch, with broader post-quantum protections and opt-in confidential transactions with view keys currently in development.
• ▪Gas fees on Arc are paid in USDC, which has over $74 billion in circulation, rather than a volatile native network token.
• ▪Arc is EVM-compatible, utilizing the Rust-based Reth execution client developed by Paradigm, which allows existing Solidity smart contracts to run without modification.
• ▪Arc utilizes the Malachite consensus engine, which implements Tendermint-style Byzantine Fault Tolerant consensus to deliver deterministic transaction finality in approximately 350 milliseconds.

Protocol integrations

• ▪BlackRock's BUIDL fund and Circle's USYC are available on Arc at launch to serve as tokenized collateral for trading and lending.
• ▪Arc's day-one ecosystem includes integrations with decentralized finance protocols Aave, Morpho, and Uniswap to provide lending, collateral, and trading infrastructure.