Bernstein sees tariff-driven copper stockpiling unwinding and prices moving toward $11,000/t

Overview

This Global Metals & Mining report examines whether US refined-copper tariffs will be imposed, how tariff expectations have reshaped global inventory locations, and what an unwind would mean for copper pricing and copper equities. Bernstein’s base case is no tariffs or tariff waivers, which it considers materially bearish for copper relative to current prices.

Core views

Bernstein traces the current copper rally to US tariff expectations rather than a durable change in underlying physical tightness. Copper has surged to $14,800/t as traders positioned for a prospective 15% tariff on refined copper from January 2027, potentially rising to 30% from January 2028. The report notes that a June 2025 call for 50% tariffs was not implemented, the June 30, 2026 report-back deadline passed without a copper-tariff announcement, and a September 10 Reuters report said the White House had not decided because of the inflation impact. Bernstein argues that tariffs would not create additional US mining or smelting capacity during the remainder of the Trump administration, while trade deals or waivers could better meet resource-independence objectives. Its base case remains no tariffs; it also views country or US-operator waivers as a rational compromise. The central evidence is the scale and location of inventory. Since July 2025, traders have moved about 600kt of additional copper into COMEX warehouses, lifting COMEX stocks from a typical roughly 100kt to about 700kt. Across exchanges, COMEX inventories rose 500kt, LME inventories 140kt, and SHFE inventories fell 30kt, leaving total exchange stocks up 615kt to 990kt. Total refined-copper inventories rose from 1.4Mt at end-2024 to 1.9Mt in July 2026, with the increase attributed entirely to COMEX builds. Meanwhile, non-exchange inventories have remained comparatively stable at 911kt-1,140kt since 2022, which Bernstein interprets as evidence that the COMEX build represented additional apparent demand rather than merely a rotation of existing stocks. If tariffs are not imposed, Bernstein expects the excess COMEX material to pressure prices as traders unwind positions. US producers and consumers typically hold only around 35kt of inventory, and non-exchange stocks historically represent 25-30% of total US copper inventories, so the report does not expect domestic buyers to absorb the excess. Much of the metal would therefore likely flow back to LME warehouses. Bernstein estimates that total inventories are equivalent to roughly 25 days of demand; at that level of tightness, it considers a 60-80% premium to the 90th-percentile cost producer fair. This gives an implied price of about $11,125/t and supports its retained CY27 copper forecast of $11,000/t. The report contrasts this with copper trading at a 136% premium to the 90th-percentile cost producer despite exchange inventory of around 13 days of demand. The futures curve indicates that traders assign little near-term probability to tariffs but retain some longer-dated tariff risk: COMEX December 2026 copper trades only 1.4% above LME December 2026, while the December 2027 premium widens to 6.7%. Bernstein outlines a bullish alternative in which a 15% tariff triggers another rush into COMEX before year-end, potentially taking copper back to previous highs and above $15,000/t. Tariffs combined with trade agreements for Chile and Indonesia could initially raise copper prices but later benefit US miners such as Freeport-McMoRan through reduced or zero import tariffs. A waiver for US companies producing overseas could preserve some protectionism while reducing copper prices. The report also argues that earnings and valuations leave copper equities exposed if tariff expectations fade. Copper industry EBITDA margins are about 73%, above the 54% long-term average since 2004 and the 58% average since 2023. Bernstein observes that purchases made when margins exceeded 70% have historically produced negative long-term returns, although margins are less predictive over a one-year horizon because momentum and macro factors can dominate. Copper prices rose 5.6% over the prior three months, supporting EBITDA estimate revisions, while equity multiples also expanded on investor enthusiasm for the copper theme. Most copper equities remain above their five-year average valuation multiples, and consensus CY27 copper forecasts of $13,500-13,800/t appear too high under Bernstein’s no-tariff scenario. It therefore maintains its $11,000/t CY27 forecast and Market-Perform ratings on FCX and ANTO.

Analysis framework

Bernstein first reviews the tariff-policy timeline and possible outcomes, then tests whether copper inventory changes reflect real supply-demand tightness by separating exchange and non-exchange stocks. It benchmarks the copper price against inventory days and the 90th-percentile cost curve, examines COMEX-LME forward spreads for tariff expectations, and connects copper prices and margins to earnings revisions and equity valuation multiples.

Methodology notes

• Industry AnalysisSupply-demand framework

  Inventory-based supply-demand analysis

  The report compares exchange and non-exchange copper inventories, inventory days, and inventory location to distinguish tariff-related stockpiling from fundamental market tightness.

• Industry AnalysisCost curve analysis

  Copper price premium to the 90th-percentile cost producer

  Bernstein uses the historical relationship between inventory tightness and the premium over the high-cost end of the copper cost curve to estimate a fair price range.

• Valuation methodsEV/EBITDA valuation

  Five-year EV/EBITDA multiple comparison

  The report compares copper-equity valuation multiples with their five-year ranges and assesses them alongside elevated copper EBITDA margins and CY27 price expectations.

Asset mapping & comparison

Structured mapping from thesis to named assets (strengths, weaknesses, peers, risks).

• Freeport-McMoRan (FCX)

  Covered copper producer; maintained Market-Perform, with potential benefit if tariffs are paired with trade agreements covering Chile and Indonesia.

  Strengths

  Exposure to Chile and Indonesia could support lower- or zero-tariff copper imports under relevant trade agreements.

  Weaknesses

  Bernstein’s no-tariff copper-price scenario implies lower sector earnings expectations.

  Comparison

  Maintained Market-Perform alongside ANTO and several other copper-related equities.

  Risks

  A tariff-driven copper-price rally could persist if tariffs materialize.

• Antofagasta (ANTO)

  Covered copper producer; maintained Market-Perform.

  Weaknesses

  Consensus CY27 copper assumptions and current sector valuations appear elevated under Bernstein’s no-tariff case.

  Comparison

  Maintained Market-Perform alongside FCX.

  Risks

  Earnings expectations are sensitive to the tariff outcome and copper-price normalization.

• Rio Tinto (RIO)

  Covered mining company; maintained Outperform.

  Strengths

  Maintained Outperform rating.

  Comparison

  Rated Outperform, unlike the Market-Perform-rated copper peers cited in the report.

• Newmont (NEM)

  Covered mining company; maintained Outperform.

  Strengths

  Maintained Outperform rating.

  Comparison

  Rated Outperform with Barrick, Rio Tinto and Merdeka Gold.

• Barrick Mining (B)

  Covered mining company; maintained Outperform.

  Strengths

  Maintained Outperform rating.

  Comparison

  Rated Outperform with Rio Tinto, Newmont and Merdeka Gold.

• Merdeka Gold (EMAS.IJ, 6228.HK)

  Covered mining company; maintained Outperform.

  Strengths

  Maintained Outperform rating.

  Comparison

  Rated Outperform with Rio Tinto, Newmont and Barrick.

• BHP Group (BHP)

  Covered mining company; maintained Market-Perform.

  Comparison

  Maintained Market-Perform with Anglo American, Antofagasta, Boliden, FCX, Glencore and Vale.

• Vale (VALE)

  Covered mining company; maintained Market-Perform.

  Comparison

  Maintained Market-Perform with other cited diversified and copper miners.

Key data

• Copper price$14,800/tCurrent price cited as having surged on tariff-driven supply movement into the US.
• COMEX copper inventory~700ktUp from a typical ~100kt; about 600kt of additional copper has moved into COMEX since July 2025.
• Total exchange inventory990ktUp 615kt since July 2025; inventories peaked at 1.3Mt in March before LME and SHFE drawdowns.
• Total refined-copper inventory1.9MtJuly 2026 level, up from 1.4Mt at end-2024; Bernstein attributes the increase to COMEX warehouse builds.
• Fair copper price estimate~$11,125/tBased on roughly 25 days of total inventory and a 60-80% premium to the 90th-percentile cost producer.
• CY27 copper forecast$11,000/tBernstein’s maintained forecast under its no-tariff scenario, versus consensus of $13,500-13,800/t.
• Copper EBITDA margin73%Above the 54% long-term average since 2004 and 58% average since 2023.
• COMEX-LME futures premium1.4% for Dec-26; 6.7% for Dec-27Bernstein interprets the curve as low near-term tariff probability but some longer-dated tariff risk.

Impact & implications

Under Bernstein’s no-tariff base case, tariff-related COMEX stockpiles should unwind, likely moving copper back toward $11,000/t and challenging elevated CY27 consensus assumptions. The report sees copper-equity valuations as vulnerable because most trade above five-year average multiples while margins are already unusually high; tariffs remain the key upside alternative.

Risks

• A 15% refined-copper tariff could trigger another rush to COMEX inventory and lift copper above $15,000/t.
• A prospective increase to a 30% tariff from January 2028 could sustain COMEX inventory building through 2027.
• Tariff waivers or trade agreements could produce outcomes that differ materially across copper producers and importers.

What to watch

• White House decisions on refined-copper tariffs, trade agreements, and potential waivers.
• The release or continued accumulation of COMEX copper inventory and any associated flow back to LME warehouses.
• COMEX-LME futures premiums, particularly the longer-dated spread that reflects tariff expectations.
• Whether copper prices and equity valuations continue to diverge from inventory levels, cost-curve benchmarks, and elevated-margin history.