Circle Launches Arc Mainnet, a USDC-Native Layer 1 Backed by BlackRock, Visa, Mastercard as Validators

Circle has launched the mainnet for Arc, a layer-1 blockchain built around its USDC stablecoin, with a validator set that includes BlackRock, Mastercard, Visa, DTCC and ICE, according to a Circle press release yesterday.

Chief executive Jeremy Allaire called it "the single most significant launch in Circle's history since USDC itself," describing Arc as "an open, neutral, always-on economic operating system" for financial markets and AI-driven transactions.

Arc is fully EVM-compatible, letting existing Solidity contracts run without modification, and departs from most layer-1 designs by charging network fees in USDC rather than a separate volatile token. A native ARC token, with a fixed supply of 10 billion, instead functions as a coordination mechanism for network security, utility and governance, while transaction fees stay denominated in USDC. The chain currently runs on a proof-of-authority model, with Circle planning a shift to proof of stake in 2027, and offers sub-second, deterministic finality alongside an optional privacy feature, still in development, that would let institutions shield transaction details behind view keys. Circle said Arc's testnet processed more than 700 million transactions in under a year of operation ahead of the mainnet launch.

Eleven institutions serve as founding validators: BlackRock, DTCC, Galaxy, ICE, Mastercard, MoneyGram, SBI Group, Standard Chartered, Sumitomo Corporation, Visa and Worldpay. More than 100 applications and institutional integrations went live alongside the mainnet, spanning banks including BNY, HSBC, Societe Generale and State Street; exchanges Binance, Coinbase, Kraken and OKX; DeFi protocols Aave, Morpho and Uniswap; custody providers Anchorage, BitGo and Fireblocks; and wallets including MetaMask, Phantom and Ledger.

BlackRock's Robbie Mitchnick said "purpose-built blockchains can help accelerate adoption of digital asset use cases, and Arc appears clearly well positioned to serve stablecoin and payment use cases at scale." Aave Labs founder Stani Kulechov said the network brings "the speed, stablecoin-native infrastructure needed to expand onchain credit to a much broader market," and SBI Group chief executive Yoshitaka Kitao said the Japanese financial group would "contribute to its operation and governance" as a founding validator.

Arc enters a stablecoin-settlement race that has already drawn more than half a billion dollars in dedicated funding. Tether's Plasma network launched in September 2025 prioritizing zero-fee USDT transfers and reached $5.5 billion in total value locked within its first week, while Stripe-backed Tempo, live since March, runs without a native token at all and instead pays validators directly in stablecoins, according to BlockEden's overview of the sector. Where those networks compete mainly on payments throughput, Circle is pitching Arc's institutional validator set and features like its StableFX cross-currency settlement product as the basis for capital-markets use cases, including tokenized treasury funds and, per Allaire, commerce conducted directly by AI agents.