Market diagnosis: Copper set a fresh all-time high at $14,545/mt LME Cash (Aug 14 close) with a $411/t cash-to-3M backwardation - the widest prompt-tightness signal since the 2021 squeeze. The August breakout is tariff-driven and supply-constrained: LME stocks fell for a 42nd consecutive day to 204,975 t with nearly half cancelled; SHFE warrants collapsed to ~69 kt, the lowest since February 2024; COMEX inventory hit a record 667 kt as traders front-run a pending Section 232 refined-copper decision. The Commerce recommendation (15% from Jan 2027, 30% from Jan 2028) was delivered June 30; the President has not acted as of August 17. Mine supply keeps missing: Grasberg lost ~270 kt in 2026, Kamoa-Kakula cut guidance to 290-310 kt, Quebrada Blanca to 200-235 kt, and Chile output is tracking -2.6%. Concentrate economics remain the tightest link: 2026 benchmark TC/RC at $0/t with spot at -$175.7/t. Societe Generale puts the market-implied probability of the 15% tariff at only ~15%, so the premium is fragile; ING warns part of the rally is tariff-expectation premium that could unwind if the decision is delayed, narrowed, or exempts refined copper. Buyers should lock 60-70% of Q3-Q4 at current levels and keep 25-30% flexible for the tariff binary.