Circle has launched the public testnet for its Arc Layer-1 blockchain, designed to enhance institutional settlement capabilities. The stablecoin issuer has partnered with over 100 institutional participants, including BlackRock, HSBC, Visa, and AWS, to test the network. Arc aims to position USDC as a native gas token with sub-second finality, aspiring to become a key economic operating system for internet-based financial activities. Despite these significant partnerships, Circle's CRCL stock experienced a 2% decline, opening at $143 and falling to $140. The market reaction comes amid the launch of the testnet, highlighting investor caution despite the project's potential.