Antofagasta (LSE: ANTO) profit jumps 27%, but copper output cut exposes the risk behind record prices

Antofagasta plc (LSE: ANTO) reported a 27% increase in first-half EBITDA to $2.84 billion as higher copper prices more than compensated for weaker production, while operating cash flow surged 53% to $2.77 billion. The Chile-focused copper miner also nearly doubled its interim dividend to 30.1 cents per share from 16.6 cents a year earlier. Yet investors focused on a significant deterioration in the production outlook after Antofagasta reduced 2026 copper guidance to 625,000 to 655,000 tonnes from 650,000 to 700,000 tonnes following extreme rainfall and operational disruption at Los Pelambres. The result creates an unusually sharp tension for shareholders: copper prices are providing exceptional earnings leverage, but Antofagasta is producing fewer tonnes precisely when each tonne has become more economically valuable.

The market reaction shows how seriously investors are treating that contradiction. Antofagasta shares fell 6.78% to £37.56 on August 13, substantially underperforming the FTSE 100, and continued falling by about 4% during August 14 trading as weakness in copper prices compounded concerns about the production downgrade. The stock had traded at £40.50 as recently as August 5 and reached a 52-week high of £44.75 in February, meaning the two-day post-results decline has rapidly erased a meaningful part of the recent copper-driven valuation premium.

The sell-off does not mean Antofagasta’s first-half financial performance was weak. EBITDA, cash flow, dividend growth and net cash costs were all supportive. What changed is the market’s confidence in the volume trajectory, particularly because management had been expecting production to accelerate sequentially through the second half after output had already fallen 9.5% year on year during the first six months.

Why did Antofagasta’s earnings rise 27% even though first-half copper production fell almost 10%?

Antofagasta produced 285,000 tonnes of copper during the first half of 2026, down 9.5% from 314,900 tonnes a year earlier. Copper sales declined even faster, falling 17.3% to 267,800 tonnes, while output at Los Pelambres and Centinela was below the previous-year period. Normally, a decline of that scale would place meaningful pressure on mining earnings, particularly because fixed operating costs must be absorbed across fewer tonnes.

Copper prices changed the equation. Strong global demand, constrained supply and disruption associated with geopolitical instability pushed copper prices to record levels during the period, allowing Antofagasta to generate substantially more EBITDA despite selling less metal. First-half EBITDA rose from $2.23 billion to $2.84 billion, demonstrating the enormous operating leverage available to a producer when commodity prices rise faster than volume declines.

The financial result therefore says as much about the copper market as it does about Antofagasta’s operational performance. A 27% increase in EBITDA alongside a 9.5% reduction in production means pricing and by-product economics had to absorb a considerable operational headwind. That is attractive while copper remains elevated, but it also means investors should avoid treating the first-half earnings growth rate as purely evidence of mine-level improvement.

Operating cash flow offers another positive signal. Cash generated from operations increased 53% to $2.77 billion, helped by higher earnings and lower working capital, providing a substantial source of internally generated funding while Antofagasta is investing heavily in its growth portfolio. Citi analysts highlighted the strength of the cash position as an offset to the production downgrade, which helps explain why the current issue is more about valuation and execution than immediate financial stress.

How much has the Los Pelambres weather disruption changed Antofagasta’s 2026 production outlook?

The production downgrade is significant because it reverses an outlook management had reaffirmed only weeks earlier. On July 15, Antofagasta maintained full-year guidance of 650,000 to 700,000 tonnes and expected quarterly production to increase sequentially during the remainder of 2026 as throughput and grades improved at Los Pelambres and Centinela. The midpoint of that range was 675,000 tonnes.

The new guidance of 625,000 to 655,000 tonnes has a midpoint of 640,000 tonnes, reducing expected production by 35,000 tonnes at the midpoint. More importantly, the new upper end of 655,000 tonnes is only slightly above the previous range’s lower boundary. Investors are therefore not looking at a minor adjustment within the old forecast, but a meaningful resetting of expected output.

The trigger was Los Pelambres. Extreme precipitation affected Chile’s Coquimbo Region during July and forced Antofagasta to conduct an orderly shutdown of the mine and processing plant after intense rain and intermittent power outages began on July 18. The company initially said operations had restarted and maintained its production guidance, while noting that key infrastructure including the El Mauro tailings dam had not suffered material damage.

By the August results, the operational assessment had become less favourable. Antofagasta said pipeline platforms and water-management systems required repairs, even though major infrastructure remained intact. The distinction matters because the event did not destroy a core processing plant or tailings facility, but it reduced the amount of production the company believes it can recover before year-end.

For shareholders, Los Pelambres now becomes the main short-term operational proof point. A stable restart and improved throughput during the remainder of 2026 could contain the earnings impact, particularly if copper prices remain strong. Additional disruption would be much more consequential because the revised guidance has already removed part of the production buffer previously available to management.

Why are Antofagasta’s lower net cash costs not as straightforwardly positive as they first appear?

Antofagasta reported first-half net cash costs of $1.22 per pound, down 8% from $1.32 per pound in the comparable period. At first glance, that appears particularly impressive given weaker production because lower volumes normally push unit costs upward. The explanation is that strong by-product credits from gold and other metals offset a substantial increase in the underlying cost of producing copper.

Cash costs before by-product credits actually increased 23% to $2.85 per pound from $2.32 per pound. Management attributed the increase to higher input costs, a labour settlement at Centinela and weaker output at Los Pelambres and Centinela Concentrates. By-product credits increased 64% to $1.63 per pound, more than compensating for those pressures and leaving the reported net cash cost lower year on year.

This distinction is important for earnings quality because Antofagasta cannot control gold prices or other by-product values in the same way it can influence mine productivity, procurement or throughput. Higher by-product prices are economically valuable, but investors should not interpret a falling net cost figure as evidence that the underlying inflationary environment has disappeared.

Fuel, sulphuric acid and other mining consumables remain expensive, with Antofagasta previously increasing its expectation for full-year cash costs before by-product credits toward a range of $2.40 to $2.60 per pound. Reuters subsequently reported that the company expects full-year costs to reach the upper end around $2.60 per pound amid higher fuel prices. The same geopolitical conditions that have supported copper pricing are therefore also increasing the cost of extracting and processing it.

Can Antofagasta’s $3.4 billion capital programme still deliver the production growth investors are paying for?

Antofagasta maintained 2026 capital expenditure guidance of $3.4 billion before the latest half-year update, reflecting a period of unusually heavy investment across the portfolio. The most important programme is the Centinela Second Concentrator, which is intended to materially increase the group’s copper production once commissioned and forms a central part of management’s medium-term growth plan.

Construction remained active during the second quarter, including work on ball mills, the fines stockpile dome, the primary crusher motor system and the overland conveyor. Pre-commissioning had already begun on selected subsystems, and management said its major growth projects were progressing toward completion of commissioning during 2027. The project had also been described as on schedule and on budget during Antofagasta’s November 2025 investor site visit.

That project is strategically more important after the 2026 production downgrade because the market’s valuation of Antofagasta increasingly reflects future rather than current output. Management has previously outlined the potential for copper production to increase by more than 30% over the medium term, meaning investors have been willing to look through temporary operational variability in anticipation of materially greater scale.

The risk is that capital intensity and execution risk are arriving together. Spending billions of dollars while current output is being disrupted increases the importance of maintaining cash generation and avoiding schedule slippage. Antofagasta’s $2.77 billion of first-half operating cash flow substantially strengthens its ability to fund the programme internally, but shareholders still need the growth projects to convert investment into additional low-cost tonnes rather than simply higher depreciation and capital employed.

Why does the $900 million Zaldívar water project matter beyond extending one Chilean mine?

Antofagasta approved approximately $900 million of investment on a 100% basis during the second quarter for a new water pipeline and pumping system at Zaldívar. The project will allow the mine to transition away from continental water from mid-2028 by using reprocessed wastewater from the city of Antofagasta, while supporting the potential extension of the mine life to 2051.

Water is one of the most important long-term constraints facing Chilean copper production. Mining operations in northern and central Chile compete with communities, agriculture and ecosystems for limited continental freshwater, making desalination and wastewater reuse increasingly important to maintaining social licences and expanding production.

Antofagasta has already been investing in desalination capacity at Los Pelambres, where expansion of the seawater reverse-osmosis facility is progressing alongside the concentrate-pipeline project. These investments may not receive the same valuation attention as new concentrators, but they are essential enabling infrastructure because additional ore-processing capacity has limited value if mines cannot secure reliable long-term water supplies.

The broader investment case therefore depends partly on infrastructure that does not immediately increase copper output. Water pipelines, desalination plants, tailings systems and power connections consume capital today to preserve or unlock production years later. The quality of Antofagasta’s growth plan should consequently be judged on integrated project delivery rather than copper-processing capacity alone.

Why did Antofagasta shares fall nearly 7% when EBITDA and the dividend increased sharply?

Antofagasta shares closed at £37.56 on August 13, down 6.78%, after trading volume reached approximately 1.3 million shares compared with a 50-day average of 1.2 million. The decline left the stock 16.1% below its £44.75 52-week high reached on February 25 and also contributed to weakness across the broader London mining sector.

The scale of the move highlights the difference between backward-looking earnings and forward-looking valuation. EBITDA of $2.84 billion and operating cash flow of $2.77 billion describe what Antofagasta earned during the first half, whereas the reduced 625,000 to 655,000-tonne production range changes expectations for the period investors are now valuing. Markets can therefore punish a company reporting strong historical earnings if the same announcement lowers future operating assumptions.

The reaction has continued into August 14, with Antofagasta falling by roughly another 4% during the London session as mining shares weakened alongside copper prices. Based on the previous £37.56 close, that move placed the shares around the £36 area intraday, materially below the £40.50 level recorded on August 5.

Sentiment should nevertheless be viewed in context. The stock remains substantially above the lower end of its 52-week range and has benefited from an extraordinary rerating as copper prices strengthened. The current sell-off therefore reflects some removal of that production-growth premium rather than evidence that investors suddenly expect financial distress.

Can copper prices continue protecting Antofagasta if production remains below earlier expectations?

The first-half result demonstrates precisely why Antofagasta has become one of the London market’s highest-leverage ways to gain exposure to copper. Production fell materially, yet EBITDA increased because the realised value of each tonne rose enough to overcome weaker volumes. That operating leverage works powerfully in a rising copper market, particularly when by-product prices also improve.

The same mechanism becomes less forgiving if copper prices retreat. Lower production combined with falling copper prices and elevated underlying cash costs would remove the offset that protected first-half earnings. This is why the production downgrade matters even for investors who remain structurally bullish on copper.

The longer-term commodity thesis remains supportive. Antofagasta has identified electrification, energy security, digital infrastructure and artificial intelligence as structural demand drivers while describing the global supply environment as increasingly constrained. New electricity grids, renewable-energy infrastructure, electric vehicles and data centres all require substantial volumes of copper, while major new mines can require many years of permitting and construction before reaching production.

However, a strong commodity thesis does not remove company-specific execution risk. The highest-value outcome for Antofagasta would combine strong copper prices with rising production from Centinela, dependable Los Pelambres operations and disciplined unit costs. Relying on copper prices to compensate continually for lost tonnes would create a much more volatile earnings profile.

Key takeaways from Antofagasta’s 2026 half-year results and copper production downgrade

• Antofagasta plc reported first-half EBITDA of $2.84 billion, up 27% from $2.23 billion a year earlier as higher copper prices offset lower production.
• Operating cash flow increased 53% to $2.77 billion, providing substantial funding capacity during a period of heavy growth investment.
• First-half copper production fell 9.5% to 285,000 tonnes, while copper sales declined 17.3% to 267,800 tonnes.
• Antofagasta cut full-year copper production guidance to 625,000 to 655,000 tonnes from 650,000 to 700,000 tonnes after the July disruption at Los Pelambres.
• The midpoint of the production range has fallen by 35,000 tonnes, from 675,000 tonnes to 640,000 tonnes.
• Net cash costs declined 8% to $1.22 per pound, but underlying cash costs before by-product credits increased 23% to $2.85 per pound.
• Antofagasta nearly doubled its interim dividend to 30.1 cents per share from 16.6 cents a year earlier.
• The $3.4 billion 2026 capital programme is supporting major projects including the Centinela Second Concentrator and Los Pelambres growth infrastructure.
• Antofagasta shares fell 6.78% to £37.56 on August 13 and remained under pressure on August 14 as investors reassessed the production outlook.
• The next valuation test is whether Los Pelambres can stabilise and Antofagasta can deliver stronger second-half production while keeping major growth projects on schedule.

Does Antofagasta’s production setback change the long-term copper growth case?

Antofagasta’s half-year results reveal both sides of the investment case unusually clearly. The financial numbers demonstrate what a high-quality copper portfolio can generate when commodity prices are strong, with EBITDA rising 27%, operating cash flow climbing 53% and the interim dividend almost doubling even though copper production fell nearly 10%. That combination gives the company considerable capacity to absorb temporary operational disruption and continue funding projects intended to lift output over the medium term.

The production downgrade nevertheless deserves the market’s attention because Antofagasta was already relying on stronger second-half output to recover from a weak first six months. Los Pelambres has now reduced that recovery potential, while underlying mining costs remain exposed to fuel and consumable inflation. Investors therefore need more than another period of high copper prices to become comfortable that earnings growth is sustainable.

The longer-term thesis remains centred on Centinela, Los Pelambres and infrastructure investments capable of unlocking additional copper production in a supply-constrained global market. If those projects deliver on time and Antofagasta achieves the substantial medium-term production growth management has outlined, the July weather disruption may ultimately appear as a temporary setback within a much larger expansion cycle.

The weaker scenario is equally measurable. Further production interruptions, project delays or persistent underlying cost inflation would increase the company’s dependence on record copper prices to support earnings and cash returns. After the sharp August 13 and August 14 share-price correction, the next meaningful proof point is no longer simply the copper price. It is whether Antofagasta can turn billions of dollars of capital investment into reliable additional tonnes.