Circle (NYSE: CRCL) has set September 16 as the launch date for its Arc blockchain's public mainnet, while naming 11 founding validators that include some of the largest institutions in global payments and financial infrastructure.

The founding validator cohort comprises BlackRock, Visa, Mastercard, The Depository Trust & Clearing Corporation (DTCC), Galaxy, Global Payments, ICE, MoneyGram, SBI Group, Standard Chartered, and Sumitomo Corporation, alongside Circle itself. Several of these firms — including Visa, Mastercard, and DTCC — operate core clearing and settlement rails for the traditional financial system; as validators, they would contribute computing resources to secure the network rather than participating solely as end users. The network has been operating on a private mainnet with institutional builders and will transition to a fully public deployment next month.

Circle described the network as being secured by the institutions that operate on it, stating that this design allows Arc to "meet the trust, security, operational, and compliance standards required of critical financial market infrastructure."

Anthony Soohoo, Chairman and CEO of MoneyGram, said: "Arc reflects where the industry is heading: trusted, compliant, and unified infrastructure that makes stablecoins practical for real-world payments."

Arc's Design and Purpose

Arc is Circle's stablecoin-focused layer-1 blockchain, which the company refers to as an "economic operating system" for financial markets and, increasingly, for autonomous software agents that move money independently. Unlike general-purpose networks such as Ethereum or Solana, where institutional activity has typically occurred through standalone applications, Arc is purpose-built around stablecoin settlement rather than general-purpose computation. According to Circle, the network is currently in private mainnet with more than 100 ecosystem and institutional builders, following a public testnet that launched in October 2025.

The blockchain is built around USDC, Circle's dollar-pegged stablecoin, which had $73.3 billion in circulation at the end of the second quarter — making it the second-largest stablecoin by market capitalization. Circle says Arc provides fast settlement, transaction fees denominated in stablecoins, and built-in privacy controls. The September 16 launch will introduce a full product suite including privacy features, an agent stack for programmable finance, and support for tokenized real-world assets.

In May, Circle raised $222 million in a token presale that valued the Arc network at $3 billion. The round was led by Andreessen Horowitz, which contributed $75 million, with additional participation from BlackRock, SBI Group, and Standard Chartered Ventures — several of which now appear on the validator list.

BlackRock's BUIDL and DTCC Tokenization Plans

Circle stated that BlackRock intends to deploy its BlackRock USD Institutional Digital Liquidity Fund (BUIDL) on Arc through the network's native USDC integration, enabling institutional investors to subscribe to, redeem, and deploy fund assets within a single on-chain environment. BUIDL is already available on other blockchain networks, and its planned addition to Arc would extend the fund's multi-chain footprint.

Additionally, Circle is collaborating with DTCC to enable the tokenization of assets held at The Depository Trust Company on Arc, with implementation expected to begin in the second half of 2027. This would allow market participants to use third-party applications on Arc for stablecoin-native settlement while referencing DTC-tokenized assets, while maintaining the same investor rights and protections as traditionally held securities.

BNY and Standard Chartered are also exploring integrations with Arc spanning custody, stablecoin access, and FX and repo infrastructure.

Timing Alongside Q2 Results

The mainnet launch and validator announcement coincide with the release of Circle's second-quarter 2026 results. The company reported $701 million in total revenue and reserve income, up 7% year over year, and $48 million in net income from continuing operations. USDC on-chain transaction volume reached $14.8 trillion during the quarter, a 151% increase from the same period a year earlier.

In July, Circle received final approval from the Office of the Comptroller of the Currency to operate a national trust bank under the name Circle National Trust. In the same month, the New York Department of Financial Services granted the company a limited purpose trust charter. Together, these credentials place Circle among a limited set of digital asset firms holding both federal and state trust charters.

More recently, Circle acquired the majority of IBM's blockchain patent portfolio, making it the largest U.S. holder of such patents. Arc was named as one of the products the acquired patents would support.