The threat of potential US tariffs on refined copper has significantly reshaped global copper trade flows, leading to a substantial premium on the CME's U.S. copper contract compared to prices on the London Metal Exchange (LME). This arbitrage opportunity has incentivized traders to redirect copper shipments towards the United States, effectively pulling metal from the global supply chain. A notable consequence of this dynamic is the draining of China's bonded warehouse zones, as copper stored there is re-exported to meet the demand generated by the US premium. China, typically the world's largest copper importer, witnessed its refined copper exports surge to record levels last year, with November shipments alone reaching 143,000 metric tons, a new annual record. A significant portion of these exports, particularly 57,700 tons in November, was destined for the U.S. and originated from stocks held in bonded warehouses at major Chinese ports. The US administration's decision on imposing tariffs on refined copper has been deferred until June 2026, but the lingering uncertainty continues to distort global trading patterns. This shift has also led to a massive accumulation of copper in CME warehouses, which now hold over 450,000 tons, surpassing the combined inventories of the LME and Shanghai Futures Exchange. As a result, China's net pull on copper from the rest of the world contracted by 11% in the first eleven months of 2025, as it struggled to compete with the U.S. premium, leading to a diversification of its supply sources towards countries like Russia and the Democratic Republic of Congo. This re-routing of supply is occurring amidst a period where global copper prices have touched record highs, driven by supply concerns and robust demand from the green energy transition.