The White House has not yet decided on refined copper tariffs, as officials weigh boosting U.S. production against higher manufacturing costs ahead of the midterms. Copper prices have already hit record highs as buyers stockpile supplies ahead of potential tariffs. The proposed duties could support U.S. miners and smelters, but risk raising costs for manufacturers and worsening global supply tightness. 10-SEP-2026 06:33 AM ET