Stablecoins are entering their least exciting and most important phase. Definitions. The U.S. Treasury has now proposed the rules that start defining when a payment stablecoin is issued in the U.S., who can offer or sell it, and how foreign issued stablecoins can reach American users. This is where regulation stops being a headline and starts becoming market structure. For issuers, exchanges and payment companies, definitions like these can determine which products can be distributed, where they can operate and what compliance infrastructure they need. Crypto spent years asking for regulatory clarity. Now the advantage may belong to the companies that understand the rulebook fastest and build around it. The next stablecoin winners will not be decided by liquidity alone. Distribution and compliance are becoming part of the moat.