In the quiet calculus of electrical infrastructure, a panel builder's choice of copper busbar supplier carries the weight of a nearly twenty-billion-dollar global market—one where China's dominance in copper processing has made it the world's foremost source of the conductors that keep power flowing through distribution panels. Copper's reign reflects not fashion but physics, even as aluminum and laminated alternatives grow faster in cost-sensitive and high-density applications. The deeper question for any buyer is not which country or material to trust, but whether the documentation behind a