Circle opens the mainnet of its own blockchain, Arc, to the general public on this September 16, 2026. For you as an investor, exactly one thing changes for now: an additional entry will gradually appear in the withdrawal menus of exchanges and in the network lists of wallets, and it lets you send USDC. Before you click that entry for the first time, four points are worth a checking look: the network data, the fee model, the bridge and the address.