Chinese rare-earth suppliers are quietly restricting shipments to U.S. customers ahead of Sept. 24 trade talks, creating a geopolitical scarcity premium that could drive up domestic rare-earth mining stocks ($MP, $UUUU, $USAR) even before any formal restrictions are announced. Key risks include trade talks succeeding (removing the catalyst), China not formally restricting exports, and broader market volatility offsetting the rare-earth thesis.