Copper's Rally Lost Its Tariff Shield Over a Year Ago. So What's Actually Holding the Price Up?

A bull market built on a tariff that never arrived is a bull market with a gap in its foundation, and that gap is now visible. Copper has spent much of the past eighteen months in one of its strongest advances in a decade, and the rally is starting to look harder to defend on fundamentals alone.

The setup is worth restating plainly. Through the first half of 2025, traders shipped record volumes of refined copper into United States warehouses, front running an expected blanket tariff on the metal under a Section 232 national security review. COMEX futures traded at a historic premium to the London benchmark as the arbitrage window opened. Then, in July 2025, the actual proclamation landed: a 50% tariff on semi-finished copper products such as wire, tube and rod, with refined cathode explicitly exempted. The premium that had justified the frontrunning evaporated almost as fast as it built. What was left behind was a bloated stockpile of US copper and a price still disconnected from the policy story that built it.

The mechanism: price without a floor

A tariff on a physical commodity does two things to its price. It creates a regional scarcity premium, and it gives that premium a policy floor that traders can underwrite with conviction, because a government proclamation is a known, durable input. Remove the tariff on the commodity itself and leave it only on downstream products, and you remove the floor without removing the price. What remains has to be justified by something else: a genuine physical deficit.

That deficit case is real but it is also fragile in a different way. Supply has tightened on its own terms. A major flooding incident at Freeport McMoRan's Grasberg complex in Indonesia in 2025 knocked out a significant share of one of the world's largest copper and gold mines for an extended stretch, and Chilean output has wrestled with its own operational setbacks. Demand has been reframed around grid buildout, electrification and the copper intensity of new data center capacity. Both of those are credible, structural stories. Neither of them comes with the policy backstop that a tariff provides. A mine restart timeline can move. A data center buildout schedule can slip. A government proclamation, once signed, does not.

The second-order effect

This is a positioning story, not a demand story. The frontrunning of 2025 left US copper inventories well above where they sat before the tariff scare began, and that stock has to clear through the system before the domestic premium can reassert itself, tariff or no tariff. A market priced for structural scarcity while sitting on an inventory overhang is a market with two narratives fighting for control of the tape at the same time. Futures positioning is now described as cautious, with traders unwinding length rather than adding to it, and that unwind is itself the evidence. Conviction does not usually erode on good news. It erodes when the story that justified the position stops being the story that is actually driving the price.

From a delta-neutral book, this is precisely the kind of divergence worth watching rather than trading directionally. We read commodity volatility that detaches from its original catalyst as a signal about realized versus implied vol, not as an invitation to pick a side in the underlying. When the fundamental narrative shifts under a price that has not moved, the options market is usually the first place that mispricing shows up, because gamma prices the distribution of outcomes, not the story attached to the spot level.

The honest counter case

The bull case does not need a tariff to survive. If the Grasberg disruption proves more durable than currently modeled, if Chilean grades keep declining faster than new projects replace them, and if data center and grid capital expenditure holds through a tighter rate environment, copper can stay structurally tight on fundamentals that have nothing to do with trade policy. A commodity cycle can be real even when one of its original catalysts turns out to be a false signal. The tariff exemption removed a prop, not the entire structure. Calling this rally dead on that basis alone repeats the same category error the frontrunners made in reverse: treating a policy input as a permanent feature of the fundamental story.

What Komey Tetteh is watching from here is the inventory drawdown pace in US warehouses against the rate of new supply disruption. If US stocks clear faster than fresh mine outages accumulate, the structural case strengthens independent of any tariff. If they do not, the gap between the narrative and the positioning widens further. Those two clocks, inventory drawdown and mine outage accumulation, are the ones that will move price before the headlines catch up.