South32 Limited

The Business

South32 is a diversified base-metals miner across five operations spanning three continents. Its Sierra Gorda copper mine in Chile, a 45%-owned joint venture, generated the highest margin in the group in FY26. Cannington in Queensland supplies silver, lead and zinc from a mine now approaching the end of its economic underground life. Manganese operations in Australia and South Africa round out the portfolio, alongside Hermosa, a construction-stage zinc-silver-lead project in Arizona. Divesting the Worsley alumina refinery and Brazilian aluminium assets removes a lower-margin business and leaves a smaller, structurally higher-margin company.

Recent Performance

South32 shares have re-rated sharply as copper and silver prices surged, with FY26 net profit reaching US$1,032 million and earnings per share of US$0.229, the strongest result in years. That strength was overwhelmingly price-driven: production volumes were broadly flat while realised copper and silver prices sat well above historical averages. The market has extrapolated that price strength into the multiple it is willing to pay, pushing the stock to a premium against mining peers rarely seen in the company's trading history.

Outlook

Group revenue is expected to ease modestly over the next two to three years as normalising copper and silver prices offset early production from Hermosa, before growth resumes as that project ramps toward full output. EBITDA margins are likely to compress from FY26's elevated 41.1% level toward the mid-30s percent range as commodity prices revert closer to mid-cycle norms. Earnings per share is expected to fall sharply in FY27 before stabilising, with Hermosa's ramp toward full production becoming the primary growth engine later in the decade and eventually contributing a meaningful share of group EBITDA.

Key Risks

Commodity price reversion is the dominant risk to the thesis. Copper and silver currently trade near the top of their historical ranges, and a meaningful pullback in either would compress group earnings materially given South32's status as a price-taker across every commodity it produces. Hermosa's large construction budget, with the majority of spend still ahead, carries execution risk, compounded by a chief executive who is less than a month into the role during the project's most capital-intensive phase. Separately, South32 trades at a premium multiple to its mining peer group with no clear precedent in its own trading history, which leaves the share price exposed to a re-rating independent of operating performance.

What to Watch

The thesis-defining signal is the trend in LME and Shanghai copper inventories over the next six to twelve months, which will indicate whether current prices reflect a genuine supply deficit or a speculative peak.

• H2 FY27 Alcoa transaction completion — closes the aluminium exit and confirms the post-sale capital framework.
• H1 FY28 Cannington open pit final investment decision — sanctioning would extend mine life and add optionality to the growth pipeline.

Company Description

South32 operates five core businesses. Sierra Gorda, a 45%-owned Chilean copper mine, is the largest earnings contributor and lowest-cost operation in the portfolio. Cannington, in outback Queensland, is one of the world's largest silver-lead-zinc mines but is approaching the end of its economic underground life around FY33. Manganese operations in Australia and South Africa supply steelmaking inputs and are the lowest-margin part of the group. Hermosa, under construction in Arizona, will add zinc, lead and silver production from FY28. The pending sale of the Worsley alumina refinery and other aluminium assets to Alcoa will remove roughly half of group revenue and concentrate the company on base metals.

Where the Growth Is

Hermosa's Taylor deposit is the single most important driver of South32's future earnings. It contributes nothing to group EBITDA today but is expected to supply a substantial share of it by the early 2030s once fully ramped. First production is targeted for the second half of FY28, reaching steady-state output of 346,000 tonnes of zinc-equivalent by FY31. At that point, Hermosa alone is expected to add several hundred million dollars of incremental annual EBITDA, effectively replacing Cannington's eventual decline.

Competitive Position

South32's advantage rests on the physical quality of its ore bodies rather than pricing power, brand, or network effects. Sierra Gorda has roughly 20 years of remaining reserve life and Hermosa's Taylor deposit has 33 years, both in stable mining jurisdictions with established infrastructure and permitting. These deposits cannot be replicated by a competitor simply deploying capital; new tier-1 discoveries are rare and take 15-20 years to permit and build. South32 remains a price-taker in every commodity it produces, with no ability to pass through cost inflation via higher prices. This advantage looks durable for the next five to seven years, underpinned by the current growth pipeline, but not indefinitely defensible once Cannington's underground mine closes around FY33 without an approved replacement.

Management & Capital Discipline

Management has returned US$2.4 billion to shareholders since the 2015 demerger, at an average price of A$3.06 a share, well below where the stock trades today. The current 40% payout ratio is being maintained through the Hermosa construction phase, with growth capital prioritised over buybacks while the project is being built. One point in management's favour: in reporting FY26 results, the company was explicit that its earnings strength was driven by commodity price tailwinds rather than claiming structural or execution credit, a level of honesty many miners avoid at cycle peaks. The main uncertainty is a chief executive transition, with the incoming CEO less than a month into the role during the most capital-intensive phase of Hermosa's construction.

Financial Position

South32's balance sheet is a genuine strength. The company already carries net cash, and the pending Alcoa transaction is expected to add a further US$3.5 billion in net proceeds, comfortably funding the remaining Hermosa construction spend without new debt or equity issuance. This position means the primary risk to the investment case is commodity price and valuation, not solvency. Even a sustained downturn in copper and silver would not threaten the dividend or the growth pipeline; it would compress reported earnings, and the question for investors is whether the current share price already reflects that risk appropriately.