Rio Tinto plc Stock (RIO): UBS Highlights Argentina Lithium Upside as Simandou Exports Begin and a $10B Divestment Plan Takes Shape

Dec. 18, 2025 — Rio Tinto plc stock is back in the spotlight today as investors weigh a new lithium-focused take from UBS against fresh reporting from Guinea’s Simandou iron ore mega-project and the miner’s broader strategy reset under CEO Simon Trott.

On the Australia-listed line (RIO:AX), shares rose as much as 1.8% to a record high of A$143.89, after UBS said its confidence has increased in Rio Tinto’s lithium strategy following a deep dive into the company’s Argentina brine assets. UBS kept a neutral stance and an A$140 price target, noting execution discipline remains decisive even as the lithium portfolio gets clearer. ^[1]

This matters for Rio Tinto plc (LSE: RIO / NYSE: RIO) because the market is increasingly treating Rio not just as an iron ore dividend engine, but as a “big mining” business trying to build a second growth flywheel in copper and lithium—while keeping costs tight and reshaping the portfolio.

Why Rio Tinto stock is in focus on December 18, 2025

The headlines hitting Rio Tinto investors today cluster around one big theme: scale meets execution risk.

Lithium optimism (with caveats): UBS sees Rio’s Argentina brine assets as central to the lithium ambition, pointing to targeted C1 cash costs of about $5–6/kg LCE and projecting Rio could reach 10–12% global lithium market share by the mid‑2030s—if projects at Fenix and Rincon are delivered with discipline and conditions in Argentina remain stable. ^[2]
Simandou reality check: Reuters reporting from Guinea says Simandou has begun exporting iron ore, but the shift from construction to operations is triggering mass layoffs that could heighten social and safety risks around the project’s new rail corridor and local communities. ^[3]
Strategy reset: Earlier this month, Rio laid out a plan to simplify and potentially generate $5–$10 billion through divestments and productivity initiatives—while also upgrading copper guidance and outlining 2026 production ranges across its key commodities. ^[4]

Put together, the story for Rio Tinto plc stock right now is not “one metal, one cycle.” It’s a multi-commodity operator trying to stay boring where boring is profitable (Pilbara iron ore), and ambitious where ambition might actually pay (copper and lithium).

Lithium: UBS sees Argentina brine as the hinge point

UBS’s note today effectively frames Rio’s lithium bet as a cost-and-scale play with a deliberate “prove it first” cadence.

According to UBS, Rio’s Argentina brine assets are “central,” with targeted C1 cash costs of roughly $5–6 per kilogram of LCE (lithium carbonate equivalent). UBS also sets an ambitious long-run picture: 10–12% global lithium market share by the mid‑2030s, contingent on “disciplined delivery” at Fenix and Rincon and stable operating conditions in Argentina. ^[5]

The phrase UBS uses—projects must “earn the right to grow”—isn’t just a nice analyst-ism. It’s basically a mission statement for the post‑boom lithium market: capital is no longer rewarded simply for being spent.

The lithium tape is moving, too

Adding to the backdrop, a separate Reuters/TradingView item today noted that lithium carbonate prices have risen in recent weeks, citing a Chilean agency report that put the value around $10,500/ton on Dec. 10 (up about 13% versus end‑October), though still below last year’s average. ^[6]

For Rio Tinto stock, that kind of price move doesn’t “solve lithium,” but it does reinforce why investors keep re-opening the question: Is the trough behind us—or just taking a breather?

Simandou: exports begin, but layoffs dominate today’s narrative

While lithium is giving Rio Tinto a growth narrative, Simandou is giving it a scale narrative—and, right now, a social-risk narrative.

Reuters reporting today from Guinea says Simandou has begun exporting iron ore after decades of delays, but is also laying off thousands of workers as construction winds down. Employment peaked at over 60,000 jobs during 2024–2025, while fewer than 15,000 will be needed to run the mines, port, and the 670 km railway built for exports. ^[7]

Key details investors are watching:

The project is run by two consortia, one led by Rio Tinto and another by the Winning Consortium Simandou (WCS). ^[8]
Rio Tinto’s Simfer venture is responsible for two mine blocks plus portions of rail and transshipment infrastructure; Rio said it provided employment to about 25,000 workers over the construction phase and expects around 6,000 workers for operations at the mine and a port terminal. ^[9]
Reuters reports growing concern among sources about social unrest and accident risk amid rapid demobilisation, including the possibility of rail blockades and community tensions. ^[10]

Simandou’s long-term promise is enormous—Reuters notes ambitions of around 120 million metric tons per year (about 7% of global demand). But today’s story is more immediate: whether Guinea can absorb the employment shock without destabilising the operating environment. ^[11]

For Rio Tinto plc stock, Simandou is a “win” only if it becomes a reliable, scalable, low-disruption supply source—not merely because it exists.

Strategy reset: $5–$10B divestment potential, cost discipline, and more copper

Rio’s early-December strategy day remains the other major reference point shaping how investors interpret today’s headlines.

Reuters reported that CEO Simon Trott outlined plans to generate $5–$10 billion through divestments and productivity, as the miner simplifies its structure and focuses on more profitable assets. Rio identified assets it does not need to own, and flagged that titanium and borates are among businesses being tested in the market. ^[12]

Rio also pointed to $650 million in annualised productivity gains and cost savings, with $370 million already realised and the remainder expected in the first quarter, according to Reuters. ^[13]

Buybacks, governance, and Chinalco

One underappreciated stock driver is mechanical rather than geological: Rio said it is working with major shareholder Chinalco to resolve governance constraints that limit Rio’s ability to buy back shares. ^[14]

If that constraint eases, investors may re-price the optionality around capital returns—especially in periods when commodity prices support excess cash generation.

Copper guidance upgrade

Copper is where Rio is trying to look like the future while still being Rio.

Reuters reported that Rio raised its 2025 consolidated copper production forecast to 860,000–875,000 tonnes, from 780,000–850,000 tonnes, citing stepped-up operations at Oyu Tolgoi. For 2026, Rio expects 800,000–870,000 tonnes. ^[15]

Those numbers also appear in Rio’s own strategy-day materials. ^[16]

Rio Tinto 2026 production guidance: what the company is targeting

For investors who like their mining stories with fewer adjectives and more numbers, Rio’s published production ranges are the map.

From Rio Tinto’s strategy-day release, the company’s 2026 guidance includes: ^[17]

Total iron ore sales:343–366 Mt
- Pilbara:323–338 Mt
- Simandou:5–10 Mt
- IOC:15–18 Mt (100% sales)
Copper (consolidated):800–870 kt
Bauxite:58–61 Mt
Alumina:7.6–8.0 Mt
Aluminium:3.25–3.45 Mt
Lithium (LCE):61–64 kt
Capex guidance: about $11bn for 2025, up to ~$11bn for 2026, and up to $10bn/year in the mid-term (2028+) ^[18]

Rio also stated an ambition for unit cost reductions over the second half of the decade and argued EBITDA could rise materially by 2030 based on long-run consensus prices—though, as always, forward-looking statements come with the usual mining-sized asterisks. ^[19]

Project pipeline watch: Rhodes Ridge, Tomago, and “green iron” experiments

Beyond Simandou and lithium, several nearer-term developments are shaping how markets think about Rio Tinto’s risk profile and optionality.

Rhodes Ridge: a long-life Pilbara reinforcement

Rio’s Rhodes Ridge joint venture approved a $191 million (A$294 million) feasibility study to progress the first phase of the project, assessing an initial 40–50 Mtpa operation. The JV partners (Rio Tinto 50%, Mitsui 40%, AMB Holdings 10%) also intend to spend a further $146 million on exploration between 2026 and 2028; the feasibility study is expected to conclude in 2029. ^[20]

Rio’s own project page adds that, subject to approvals, first ore from the initial development is expected by 2030, and that Rhodes Ridge could support a world-class hub in the long term. ^[21]

Tomago aluminium: government support to keep it alive past 2028

In Australia, Reuters reported the federal government unveiled a rescue initiative for the Tomago aluminium smelter (majority owned by Rio Tinto), including work to secure a long-term, fixed-price energy supply and concessional finance to accelerate renewables and storage. Tomago is expected to invest at least A$1 billion over the next decade in capital, maintenance, and decarbonisation efforts as part of the arrangement. ^[22]

For Rio Tinto plc stock, energy cost certainty in aluminium can matter nearly as much as aluminium prices, because power is a dominant input cost.

Green iron: Rio-linked decarbonisation moves from talk to paperwork

A particularly “Discover-friendly” subplot: Rio is tied into an early-stage green iron demonstration effort in Western Australia with Calix.

An ASX announcement from Calix dated 15 December 2025 said Rio Tinto completed due diligence under their Joint Development Agreement for the Zesty Green Iron Demonstration Project, clearing the way for an initial A$3 million cash contribution from Rio. The announcement describes Zesty as combining electric heating and hydrogen reduction, with a demonstration plant designed to produce up to 30,000 tonnes per annum of H2‑DRI or HBI, and notes support from an ARENA grant of up to $44.9m, subject to matched funding. ^[23]

This won’t move next quarter’s earnings, but it does feed the longer-run investment case: can Rio keep selling iron units into a world that increasingly prices carbon?

Legal and geopolitical backdrop: not the fun part, but it’s real

Rio Tinto’s operating footprint is global, which means its risk surface is… creatively multidimensional.

Rusal lawsuit: Russian court ruling adds friction

Reuters reported a Russian court ruled in favour of Rusal in a 104.75-billion-rouble (~$1.32 billion) lawsuit tied to the Queensland Alumina Ltd (QAL) refinery dispute, with Rio saying the claim attempts to re-litigate matters already decided by an Australian court and calling the Russian proceedings an abuse of process. ^[24]

Rio stated it would continue to defend its position and take steps to protect its rights and assets. ^[25]

US critical minerals policy: supportive tone for copper projects

In Washington, Reuters reported the Trump administration plans more “historic deals” with the mining sector to boost domestic production of critical minerals and reduce reliance on China. The report specifically mentions interest in accelerating projects in Arizona, including a major copper project planned by Rio Tinto and BHP. ^[26]

Policy support doesn’t guarantee permits, timelines, or social license—but it can change the financing and strategic value of long-dated copper optionality.

Rio Tinto stock forecast: what analysts are saying right now

Analyst views coming into the end of 2025 are still best described as constructive, but not euphoric—which is often when commodity equities become interesting.

UBS (today): Neutral rating, A$140 price target on the Australia listing; thesis centers on execution discipline in lithium, low-cost Argentina brine potential, and the possibility of meaningful global market share over time. ^[27]
Berenberg (reported): TipRanks/TheFly reported Berenberg raised its Rio Tinto price target to 5,300 GBp (from 5,200 GBp) while keeping a Hold rating. ^[28]

Meanwhile, Rio itself is effectively offering a corporate “forecast” via guidance and capital plans—highlighting volume growth, portfolio focus, and cost discipline as the levers that could drive returns through the cycle. ^[29]

Bottom line: the catalysts investors will keep watching into 2026

Rio Tinto plc stock is being pulled by three gravitational forces:

Iron ore scale and resilience (Pilbara today, Simandou tomorrow—if execution and local stability cooperate). ^[30]
Copper growth (Oyu Tolgoi ramp and a sharper strategic emphasis on copper as a demand-side “electrification metal”). ^[31]
Lithium credibility (Argentina brine economics, disciplined capex, and whether Rio can build a low-cost position while the market remains allergic to overbuilding). ^[32]

Layer on top the “portfolio housekeeping” (divestments), capital return constraints (Chinalco governance discussions), and a steady stream of decarbonisation and energy-cost headlines—and you get a stock that’s acting less like a single-commodity proxy and more like a macro-meets-execution barometer. ^[33]