Circle's stock price fell 17% in a single day because Wall Street decided to launch its own stablecoin. Open Standard, together with over 140 institutions including Visa, Mastercard, BlackRock, and Coinbase, announced the launch of Open USD. USDC has always been regarded as the most compliant stablecoin, but now its allies have become competitors. Under Open USD, reserve yields go to the issuer, not the users — Wall Street is turning stablecoins into its own profit center. Circle's moat is compliance and network effects, but Open USD's moat is the payment channels of Visa and Mastercard. If Open USD goes live, institutional demand for USDC may be diverted, and Circle's stock price has already priced in this concern. However, analysts believe the sell-off is excessive, as USDC still has a $74 billion market cap and first-mover advantage. The stablecoin track is shifting from "crypto-native" to "traditional financial infrastructure." Whether Circle can defend its position depends on whether it can upgrade from a payment tool to a financial protocol.