Circle launches Arc mainnet as Upbit and Bithumb open USDC transfers on the network

Circle, the issuer of USDC, opened the public mainnet of Arc, a blockchain built for financial transactions, on Sept. 16. Arc is a base-layer (layer-1) blockchain that runs on its own, like Ethereum or Solana, and its transaction fees are paid in the dollar stablecoin USDC rather than a separate token. Circle first unveiled plans for Arc in August 2025 and moved it to a full production network after nearly a year of test operations on a testnet.

Already live on Upbit and Bithumb

Circle's press release named 13 digital asset exchanges connected to Arc at launch. Alongside Binance, Coinbase, OKX, Bybit and Kraken, Upbit was the only South Korean exchange on the list. Circle said the exchanges "give users and institutions familiar, seamless access into Arc."

Upbit posted a notice at 7:46 p.m. KST on Sept. 16, the day of the launch, adding Arc as a supported network for USDC deposits and withdrawals. According to the notice, the minimum deposit for USDC on Arc is 3 USDC, the minimum withdrawal is 0.01 USDC and the withdrawal fee is 0.01 USDC. Upbit said users must issue a new deposit address for the network to deposit via Arc, and should check before withdrawing whether the receiving exchange or wallet supports Arc.

Bithumb also supports Arc, although it is not on Circle's list. As of 11:35 p.m. KST on Sept. 29, both deposits and withdrawals of USDC on Bithumb were open on the Ethereum and Arc (ARC) networks. At the same time, USDC traded at 1,352 won on Upbit and 1,351 won on Bithumb. Coinyong's kimchi premium data showed Upbit's price about 0.5% below the Binance price converted into won, a so-called reverse premium. The kimchi premium is the gap between prices on Korean exchanges and global markets. The 24-hour trading value of Upbit's USDC market against the Korean won was about 1.3 billion won, small next to the roughly 75.4 billion won traded in its Tether (USDT) won market at the same time.

Fees in dollars, finality in under a second

Circle has built Arc's design around financial transactions.

• Fees paid in USDC: Users pay fees from their USDC balance, with no need to buy and hold a separate native token whose price swings.
• Sub-second finality: Transactions are designed to become irreversible in under a second, targeting activity that needs instant settlement, such as payments and foreign exchange.
• Ethereum compatibility (EVM): Smart contracts and developer tools built for Ethereum work as they are.
• Opt-in privacy: A feature that shields transaction details and balances and discloses them only to parties that need to see them; Circle said it is still in development.

Circle's foreign exchange service, StableFX, also runs on Arc, handling cross-currency trades around the clock. The 22 local-currency stablecoins that Circle said are active or onboarding include KRW1, denominated in Korean won, alongside the Japanese yen's JPYC. Circle said the testnet processed more than 700 million transactions in under a year, and that more than 100 applications and more than 100 institutional and ecosystem builders were live on day one.

BlackRock and Visa step in as validators

A total of 11 institutions are named as founding validators that will operate and secure the network: BlackRock, the Depository Trust & Clearing Corporation (DTCC), Galaxy, ICE (parent of the New York Stock Exchange), Mastercard, MoneyGram, SBI Group, Standard Chartered, Sumitomo Corporation, Visa and Worldpay (now Global Payments). Circle said they will join in phases. Banks that Circle cited as using or exploring Arc include BNY, HSBC and State Street. In decentralized finance (DeFi), Aave and Morpho anchor Arc's lending markets from launch.

"USDC was step one. Arc is the network built for what comes next."

Jeremy Allaire, co-founder and CEO of Circle

ARC tokens minted, but no launch date

Arc is an open network that anyone can use, but for now it runs on proof of authority (PoA), in which only approved institutions take part in validation. Circle said it is exploring a transition in 2027 to proof of stake (PoS), in which anyone can stake tokens to participate in validation. To that end, it minted the network's native token in the United States, creating the full initial supply of 10 billion ARC in a genesis mint, but Circle stressed that the mint "is not a commitment to publicly launch ARC." Even if the token launches, network fees will still be paid in USDC. USDC has more than $74 billion in circulation, according to the press release.