Circle has launched StableFX on the Arc Layer 1 blockchain, bringing round-the-clock foreign-exchange trading and atomic payment-versus-payment settlement to an institutional-focused network less than a week after Arc’s mainnet went live. The service separates trade execution from settlement: eligible businesses submit a currency pair, amount and preferred settlement window through a request-for-quote process, allowing screened liquidity providers to compete offchain before both stablecoin legs are deposited into a smart-contract escrow and transferred simultaneously on Arc. Circle is targeting a global FX market that moves nearly $10 trillion daily and still relies heavily on banking-hour infrastructure. Users can choose near-instant or deferred settlement, extending activity across weekends and time zones while reducing settlement risk and the need for multiple bilateral counterparty relationships. Circle’s developer documentation currently names USDC and euro-denominated EURC, while the company has said it plans to add local stablecoin pairs without publishing a complete list of pairs available for live StableFX trading. Arc’s broader stablecoin participation list does not automatically indicate StableFX availability. Access is limited to eligible incorporated businesses, including payment companies, financial institutions and corporate treasury desks. Circle Chief Executive Jeremy Allaire described StableFX as a “strong emerging primitive” for atomically settled, real-time onchain foreign exchange. Operational benefits may include overnight liquidity rebalancing and settlement windows aligned with corporate funding schedules, though firms using partner-issued stablecoins still need arrangements for deposits, redemptions, custody and local payouts. Circle Mint provides USDC and EURC liquidity and fiat conversion in supported markets, but not automatically for tokens issued by other companies.