The periodic table of the AI stack
Every data centre is a pile of specific atoms. Fifty-six of the 118 elements have a job in it, fourteen of those are short, concentrated or behind an export licence right now, and five are newer materials trying to replace an incumbent. A map of which is which, and what each one suggests about the next bet.
the scarce thing is never the element
trying to answer →What becomes scarce when intelligence becomes cheap?Where does value move when intelligence becomes commoditized?
People describe the AI buildout in chips, gigawatts and dollars. Underneath all three it is a shopping list of elements, and the list is longer and stranger than “silicon and copper”. This is that list laid out on the one chart everybody already knows how to read.
Yellow means squeezed today. Blue is a newer material making a run at an old one. Black outline means the stack does not work without it but supply is holding. Grey means I looked and found no real role. Click any cell; the buttons above the table show one layer of the stack at a time. Every element has its own link, so you can send someone straight to one.
- No role found
17 elements in the stack that Beijing licenses or channels through state-approved exporters. The suspended parts come back by default on 27 November 2026. Open a cell for its rule.
Hydrogen
present
What it does
Carrier and anneal gas in the fab, and the gas that keeps tin off the mirrors inside an EUV machine.
Helium
squeezed now
What it does
Cools the back of every wafer during etch, finds leaks, and fills high-capacity hard drives. Nothing else does the main jobs.
~$127 (late 2025)→to$152.70 (Mar 2026)
what moved it: a war, not AI
Before AI
A market of about 190 million cubic metres a year from four places: the US, Qatar, Russia and Algeria. Chipmaking took 20 to 25% of it; hospitals, aerospace and welding took the rest.
What changed
Chipmaking’s share is projected to reach 30% by 2030 as the number of EUV layers grows. The 2026 spike itself was the Qatar outage, which took about 5.2 million cubic metres a month off the market.
The squeeze
Qatar makes about 30% of the world’s helium as a by-product of liquefied natural gas. Ras Laffan went offline in March 2026 after Iranian strikes and spot prices rose 40 to 100% within weeks. South Korea bought about 65% of its helium from Qatar.
- Who supplies
- ExxonMobil (LaBarge)QatarEnergyGazprom (Amur)LindeAir LiquideAir ProductsMesserIwatani
- Who buys
- TSMCSamsungSK hynixSeagateWestern Digital
- Who is working on it
- Renergen (South Africa)Pulsar Helium (Montana)North American HeliumDry Piney, Wyoming (2028)
The bet
Helium is about $6 of an $18,000 EUV wafer, so a fab will pay any price and still nobody upstream gets rich on price alone. The opening is reclaim (leading fabs already recover 70 to 95%) and helium that is not tied to an LNG plant.
Lithium
load-bearing
What it does
Backup power at the rack and the batteries now built beside data centres. As lithium niobate, also the fastest optical modulators (see niobium).
The squeeze
Lithium prices more than doubled between January 2025 and April 2026 on storage demand. China’s controls on batteries, cathodes and graphite anodes are suspended only until November 2026.
China
Controls on lithium batteries and cathode materials, announced in October 2025, are suspended until November 2026.
Boron
present
What it does
The dopant that makes silicon p-type, a few atoms per million. Also the B in neodymium-iron-boron magnets.
Carbon
a newer bet
What it does
Three forms matter. Diamond is the best conductor of heat there is. Graphite is the anode in backup batteries. With silicon it is silicon carbide, the switch in high-voltage power conversion.
what moved it: not a price story
Before AI
Heat left a chip through copper: a copper lid, a copper cold plate.
What changed
Chip power density is passing what copper can spread. Coherent sells a diamond-silicon carbide composite at over 800 W/m·K, twice copper. Diamond Foundry bonds thinned silicon straight onto single-crystal diamond.
The squeeze
Battery-grade graphite is on China’s suspended control list. Diamond is not short; it is unproven at wafer scale.
- Who supplies
- Element SixOrbrayDiamond FoundryCoherentAkash Systems
- Who buys
- Power-chip makersUS defence primesAI server builders
- Who is working on it
- HexSeedMIT (transistors embedded in diamond)
The bet
Heat now limits how much power a chip can take, and diamond conducts it about five times better than copper. Element Six and Orbray have a 50 mm single-crystal wafer above 2,200 W/m·K. HexSeed, in Scotland, raised £600k in August 2026 to grow diamond straight onto finished gallium nitride chips. Small rounds, early, real physics.
China
Graphite has needed a licence since the first wave of controls. Controls on synthetic graphite anodes are suspended until November 2026.
Nitrogen
load-bearing
What it does
The purge gas in every tool, the titanium nitride barrier inside every chip, and the N in gallium nitride.
Oxygen
present
What it does
The other half of every oxide: gate insulators, glass, fibre.
Fluorine
a newer bet
What it does
Etch and chamber-cleaning gases in the fab, and the fluorinated fluids used for two-phase immersion cooling.
what moved it: regulation
Before AI
3M’s fluorinated fluids were the standard for two-phase immersion cooling.
What changed
3M left, the rules tightened, and power density kept rising. Operators need a fluid that is not a PFAS.
The squeeze
The cooling fluids are PFAS, the “forever chemicals”. 3M has left the business and regulators in the US and EU are tightening.
- Who supplies
- 3M (exited)
- Who buys
- Data-centre operatorsNvidia-class rack builders
- Who is working on it
- Orbital Industries
The bet
A coolant with no PFAS in it, arriving as chip power density passes what water alone can handle. Orbital Industries raised $50M in May 2026 for one, with Nvidia’s venture arm in the round.
Neon
load-bearing
What it does
The buffer gas in the deep-ultraviolet lasers that still print most chip layers. About 70% of the world’s neon goes to lithography.
The squeeze
Ukraine shipped up to half of chip-grade neon before 2022. Since then China, Korea and Taiwan built their own supply, and laser makers added recycling.
The bet
A chokepoint that got solved, which makes it the one to study. It was fixed by recycling and by a new process (EUV uses tin, not neon), not by new sources. Expect the same shape elsewhere.
Sodium
present
What it does
Liquid sodium is the coolant in TerraPower’s Natrium reactor, part of Meta’s nuclear portfolio. Nothing is built yet.
Aluminium
load-bearing
What it does
Chassis, heat sinks, overhead transmission lines.
The squeeze
Up about a third with the other base metals between January 2025 and April 2026.
The bet
Copper’s understudy: about 60% of the conductivity at about 30% of the cost. When copper bites, busbars and transformer windings switch.
Silicon
squeezed now
What it does
The wafer. Also the glass: optical fibre, and the woven glass cloth inside every chip package.
8–10 weeks→to20+ weeks
what moved it: AI, directly
Before AI
T-glass was a niche cloth for phone-chip substrates. Nittobo’s whole electronic-materials arm sold ¥40.9bn in 2025. Data centres were under 5% of world fibre demand in 2024.
What changed
Nvidia’s interposer grew from 814 mm² to 1,700 mm² in one generation, and bigger packages need more cloth. Bank of America expects Nittobo’s segment at ¥87.7bn by March 2028 at close to 48% margin. Data centres head for about 30% of fibre demand by 2027.
The squeeze
Silicon is sand. The forms are what is scarce. One Japanese company, Nittobo, makes about 90% of the low-expansion “T-glass” cloth that keeps a large AI package flat as it heats. Prices are up 20 to 30%, laminate lead times went from 8–10 weeks to over 20, and new capacity lands in mid-2027. Fibre preforms are booked into 2027 as well.
- Who supplies
- NittoboTaiwan GlassUnitikaNan Ya PlasticsCorningShin-EtsuSumitomo ElectricYOFC
- Who buys
- NvidiaGoogleAmazonAppleMeta
- Who is working on it
- Nittobo Fukushima (tripling, mid-2027)Asahi Kasei (quartz cloth)Shin-Etsu (quartz cloth)Grace Fabric
The bet
The scarce thing is rarely the element. It is the one qualified factory that turns it into a form. Yole’s analyst names the candidates for the next T-glass: copper foil, solder mask, copper-clad laminate.
Phosphorus
load-bearing
What it does
An n-type dopant in silicon, and the P in indium phosphide (see indium).
Sulfur
present
What it does
Sulfuric acid cleans wafers. It also leaches uranium out of the ground in Kazakhstan, where acid supply has itself been a constraint.
Chlorine
present
What it does
How silicon and germanium are purified and carried: as chlorides. Silicon tetrachloride for fibre is up about 50%.
Argon
present
What it does
The inert atmosphere for growing silicon crystals and for sputtering metal films.
Scandium
present
What it does
Scandium aluminium nitride makes the radio filters in Wi-Fi and 5G chips, a few grams per wafer. On China’s April 2025 licence list. More a phone story than a data-centre one.
China
Export licence since April 2025.
Titanium
load-bearing
What it does
Titanium nitride is the barrier under every tungsten plug. Barium titanate is the dielectric in ceramic capacitors.
Chromium
present
What it does
Part of the cobalt-chromium-platinum layer that holds the bits on a hard-drive platter.
Iron
squeezed now
What it does
The transformer core, as grain-oriented electrical steel. Also the rack, and the iron in magnets and in lithium iron phosphate batteries.
about half as long (early 2020s)→to128 weeks
what moved it: grid build-out and AI together
Before AI
Transformers were a slow replacement market for utilities.
What changed
Demand for generator step-up units is up 274% since 2019 and for substation units 116%. Of roughly 16 GW of data-centre capacity announced for 2026, about 5 GW is physically under construction.
The squeeze
Large power transformers are the queue. Wood Mackenzie’s survey puts standard units near 128 weeks and substation units above 160. Core steel is up 60 to 70% since 2020, and the US has one producer, Cleveland-Cliffs. (Secondary sources; I have not read the survey itself.)
- Who supplies
- Cleveland-CliffsBaosteelNippon SteelJFE SteelPOSCOThyssenkrupp
- Who buys
- UtilitiesHyperscalersTransformer makers
- Who is working on it
- Cleveland-Cliffs Butler Works expansion (2028)
The bet
Hyperscalers have bought into power plants and pre-ordered transformers. They have not yet gone one step further, into core steel. Through 2028 the rent sits with whoever can deliver energised capacity.
Cobalt
load-bearing
What it does
Liners and contacts in advanced chips; the magnetic layer on hard-drive platters.
The squeeze
Up about 130% after the Democratic Republic of the Congo imposed export quotas.
Nickel
present
What it does
The plating under the gold on connectors and boards.
Copper
squeezed now
What it does
The conductor. Chip wiring, board traces, busbars, cold plates, transformer windings.
~$9,000 (five-year average)→to$14,728 (record, 8 Sep 2026)
what moved it: mines going backwards, with AI at the margin
Before AI
A market of about 28 million tonnes driven by construction, appliances and China, then electric vehicles.
What changed
Data-centre construction takes about half a million tonnes in 2026, of which 100 to 200 thousand is specific to AI. At the same time mine output fell 1.1% in the first half of 2026, with Codelco and Freeport both down by double digits at record prices.
The squeeze
A normal data centre embeds about 27 tonnes per megawatt (Microsoft’s Chicago campus); AI-dense halls run 30 to 45. The price set a record of $14,728 a tonne in September 2026. S&P projects a 10 million tonne shortfall by 2040.
- Who supplies
- BHPCodelcoFreeport-McMoRanGlencoreSouthern CopperRio TintoAntofagastaIvanhoe
- Who buys
- HyperscalersUtilitiesCable and busbar makers
- Who is working on it
- Navitas (800 V power, less copper)Aluminium substitution
The bet
AI is under 2% of copper demand and roughly all of this year’s growth: the marginal tonne. That cuts both ways, because a pause in AI spending removes exactly the tonne that sets the price. Copper is under 0.5% of a data centre’s cost, so buyers do not flinch. The less crowded side is whatever uses less of it: 800-volt power distribution (copper up to 45% thinner), aluminium, and fibre in place of cable.
Zinc
present
What it does
The parent. Indium and germanium are recovered as by-products of zinc refining, which is why their supply does not respond to their price.
Gallium
squeezed now
What it does
Gallium nitride switches power faster and cooler than silicon; it is in Nvidia’s 800-volt architecture. Gallium arsenide does fast I/O and lasers.
~$260 (Jun 2023)→to~$2,100 (Mar 2026)
what moved it: export controls
Before AI
About 700 tonnes a year, into LEDs and the radio chips in phones. China and Rotterdam prices sat within $50 of each other.
What changed
Gallium nitride power chips for AI servers are new demand: data centres could take up to about 10% of today’s supply by 2030. But the eightfold gap between China and Rotterdam is policy, not demand.
The squeeze
China makes about 99% of primary gallium: roughly 750 of the world’s 760 tonnes in 2024. European prices rose 365% in 2025 and sit about five times above Chinese domestic prices. The ban on US-bound exports is suspended until 27 November 2026. Shipments to Japan have been near zero all year.
- Who supplies
- Chinese alumina refiners (about 99%)
- Who buys
- NavitasPower-chip makersLaser and RF chip makersDefence radar
- Who is working on it
- Rio Tinto + Indium Corporation (Quebec, pilot 2027)Alcoa + Japan (Western Australia)ATALCO (Louisiana)Nyrstar (Tennessee)
The bet
Gallium comes out of alumina refining, and nobody outside China had a reason to recover it. The missing piece is refining, not ore. A refinery in Western Australia and the US TRACE-Ga project are the line items that change anything. The $10 billion stockpile loan buys time, not supply.
China
Export licence since August 2023. The outright ban on US-bound shipments is suspended until 27 November 2026; the ban on military end-users is not.
Germanium
squeezed now
What it does
The dopant that makes the core of an optical fibre guide light. Also strained silicon-germanium in fast transistors.
~$1,150 (Jan 2023)→to$8,597 (Feb 2026)
what moved it: export controls, then fibre
Before AI
About 240 tonnes a year, into fibre, infrared optics and satellite solar cells. Fibre already took 35 to 40%.
What changed
A GPU rack uses about 36 times the fibre of a CPU rack. If fibre deployment doubles by 2030 as forecast, fibre alone would need about three-quarters of today’s germanium.
The squeeze
Fibre takes 35 to 40% of the world’s roughly 240 tonnes a year, and a GPU rack uses about 36 times the fibre of a CPU rack. Germanium went from $2,839 to $8,597 a kilogram between January 2024 and February 2026. China produces about 60%.
- Who supplies
- China (about 60%)Umicore (recycling)CorningYOFCShin-EtsuSumitomo Electric
- Who buys
- MetaNvidiaAmazonTelecom carriers
- Who is working on it
- Corning (three new US plants)Umicore (recycling)
The bet
Meta (up to $6bn), Nvidia (up to $3.2bn) and Amazon have all written cheques to Corning. That trade is taken. What is open: recovery and recycling outside China, and (my inference, not a sourced claim) hollow-core fibre, which guides light through air instead of doped glass.
China
Export licence since August 2023. The outright ban on US-bound shipments is suspended until 27 November 2026; the ban on military end-users is not.
Arsenic
present
What it does
An n-type dopant, and the As in gallium arsenide.
Bromine
present
What it does
Used in etching circuit patterns. South Korea gets about 90% of its bromine from Israel.
Krypton
present
What it does
Krypton fluoride lasers print the older, wider layers of a chip.
Yttrium
squeezed now
What it does
Yttrium oxide lines the inside of plasma etch chambers. Without it the chamber walls shed particles onto the wafer.
under $7 (before Apr 2025)→to~$1,000 (Sep 2026)
what moved it: export controls
Before AI
Cheap and plentiful: coatings, ceramics, phosphors. Nobody tracked it.
What changed
AI did not move this price. It only made the etch tools that need the coating run flat out. The North American price is now about 196 times the Chinese one.
The squeeze
On China’s licence list since April 2025. Yttrium oxide prices rose about 6,900% in the twelve months to February 2026, and US imports from China were still down 75% a year on.
- Who supplies
- ChinaA small amount of US production
- Who buys
- Applied MaterialsOther etch-tool makersTurbine-coating makers
The bet
A rounding error in cost that sits inside the tools that make every chip. Separation outside China and recycling of spent coatings are thinly covered.
China
Export licence since April 2025, covering the metal, the oxide and other compounds.
Zirconium
present
What it does
The cladding around nuclear fuel. Purifying it for reactors is also where hafnium comes from.
Niobium
a newer bet
What it does
As thin-film lithium niobate, it turns electrical signals into light faster and with less loss than silicon can.
what moved it: not a price story
Before AI
Lithium niobate modulators were bulky telecom parts. Data-centre links used silicon photonics.
What changed
Above 800G per link silicon modulators run out of headroom, and thin-film lithium niobate can now be made on 6- and 8-inch wafers at ordinary foundries.
- Who supplies
- HyperLightXili OptoelectronicsNantOptiFabUMCWavetek
- Who buys
- MediaTekFoxconnJabilTransceiver makers
The bet
The next step after 800G links. HyperLight, out of Harvard, closed an $80M Series C in June 2026 led by MediaTek with Foxconn, Jabil and UMC: the supply chain funding its own supplier. Parts at 200G per lane are shipping and 400G is sampling. In China, Xili raised about RMB 100M for the same material. The performance numbers are the companies’ own.
Molybdenum
a newer bet
What it does
Tungsten’s successor for the finest wiring in memory and logic. It needs no barrier layer, so more of the wire actually conducts.
what moved it: not a price story
Before AI
Steel takes about 80% of the world’s molybdenum. Chips used tungsten.
What changed
Samsung has used it in 286-layer memory since April 2024, Micron is in production, and SK hynix follows with 375 layers by the end of 2026. The tonnage is tiny: Samsung’s purchases go from 4 tonnes to about 80 by 2030.
The squeeze
On China’s February 2025 licence list.
- Who supplies
- Lam ResearchTokyo ElectronAir LiquideEntegrisMerckSK Specialty
- Who buys
- SamsungSK hynixMicron
The bet
Lam Research says nearly every major chipmaker is qualifying it. The metal is cheap. The value lands with deposition tools and precursor chemicals.
China
Export licence since February 2025.
Ruthenium
squeezed now
What it does
A spacer about three atoms thick in every conventional hard-drive platter. Next in line to replace copper in the tightest chip wiring.
$560 (Mar 2025)→to$1,750 (Mar 2026)
what moved it: AI storage
Before AI
About a million ounces a year. Electronics took a third (hard drives, chip resistors) and chemical catalysts most of the rest.
What changed
Hard-drive capacity shipped is forecast to go from about 1.2 zettabytes in 2024 to over 7 by 2029, and both US drive makers were sold out for 2026.
The squeeze
From $560 to $1,750 an ounce in the year to March 2026, a record, then a peak of $1,895. The whole market is about a million ounces a year, nearly all a by-product of South African platinum mining, where output is falling. Metals Focus sees a 203,000-ounce deficit in 2026.
- Who supplies
- South African platinum minersNortham PlatinumHeraeusJohnson Matthey
- Who buys
- SeagateWestern DigitalTSMCIntelSamsung
- Who is working on it
- Seagate (HAMR drives, which drop ruthenium)
The bet
Two forces pull opposite ways. The next generation of hard drives (HAMR) needs little or no ruthenium, and Seagate expects about half its 2026 capacity to ship on it. But chip interconnect could become a new use from around the 14-ångström node. The bet is on which arrives first.
Palladium
present
What it does
Plating, and some capacitor electrodes.
Silver
load-bearing
What it does
Capacitor terminations, contacts, thermal paste. The silver market is in its sixth straight annual deficit, and China now lists 44 authorised silver exporters.
China
Not a licence: silver may only be exported by 44 state-authorised firms.
Indium
squeezed now
What it does
Indium phosphide is the laser. Silicon can steer light but cannot make it, so every optical link in an AI cluster, pluggable or co-packaged, starts at an indium phosphide chip.
$249 (2023 average)→to~$710 (Jul 2026)
what moved it: AI optics, plus speculation
Before AI
About 1,100 tonnes a year, most of it into the transparent coating on flat-panel displays. Telecom bought lasers by the hundred.
What changed
Indium phosphide is small tonnage but all of the growth. Laser orders now run to hundreds of millions. At AXT, indium phosphide is about 65% of revenue, and customers prepaid $47.7M in one quarter.
The squeeze
Lumentum says demand for its lasers exceeds supply by more than 30% and expects to sell out 2028. Its chief executive thinks the gap will be worse than memory’s. China refines about 70% of indium and put indium phosphide under licence in February 2025. In March 2026 Nvidia put $2bn each into Lumentum and Coherent.
- Who supplies
- China (760 t)South Korea (180 t)AXTSumitomo ElectricJXFreibergerLumentumCoherentIQE
- Who buys
- NvidiaHyperscalersInnoLightFabrinetApplied Optoelectronics
- Who is working on it
- Coherent (6-inch line)AXT (capacity to 2031)Veeco (tools)OpenLightYunnan Germanium
The bet
The lasers are spoken for: Coherent says it will not sell any outside the company. The constraint has moved one layer up, to substrates (AXT, Sumitomo, JX, Freiberger) and to the tools for new lines. On 6 October 2026 Lumentum put down $87M in deposits to reserve AXT wafers to 2031. The counter-view: LightCounting expected the shortage to fade by the end of 2026.
China
Indium phosphide and two indium precursors have needed a licence since February 2025. The metal itself is not listed.
Tin
load-bearing
What it does
Solder, everywhere. And the droplet of molten tin an EUV machine vaporises to make its light.
The squeeze
Fastmarkets models tin bought for AI hardware at 11.3 thousand tonnes in 2026, rising to 26.5 by 2030: about a tenth of all solder demand, against a forecast market deficit of about 9.
The bet
AI will not cause a tin shortage. It can turn the next mine disruption into one: a year of AI demand is about the size of all exchange stocks.
Antimony
present
What it does
An n-type dopant. Small in the stack, but the sharpest of China’s controls: exports fell close to zero in 2025, European prices rose 437%, and only 11 firms may export it.
China
Export licence since September 2024, through 11 authorised exporters. The outright ban on US-bound shipments is suspended until 27 November 2026; the ban on military end-users is not.
Tellurium
present
What it does
Bismuth telluride coolers hold each laser in an optical transceiver at its wavelength. A by-product of copper refining, on China’s February 2025 licence list.
China
Export licence since February 2025.
Barium
load-bearing
What it does
Barium titanate is the dielectric in ceramic capacitors, thousands to a board.
The bet
The same crystal, as a thin film on silicon, is a rival to lithium niobate for the next optical modulator. I have not sourced funding or shipment numbers for it.
Cerium
present
What it does
Ceria slurry polishes each wafer flat between layers.
Praseodymium
load-bearing
What it does
Alloyed with neodymium in permanent magnets (see neodymium).
Neodymium
load-bearing
What it does
Neodymium-iron-boron magnets turn every fan, every coolant pump and every hard-drive motor.
The squeeze
China mines about 60% of rare earths, refines about 91% and makes about 94% of the finished magnets. Neodymium itself is not on the control list; the heavy additives are.
The bet
Outside China, announced mining could reach about 50,000 tonnes by 2035, refining under 40,000 and magnet-making about 18,000. The gap widens as you go downstream, so magnets are where capacity is shortest. And this one can be designed out: ABB sells rare-earth-free motors for data-centre cooling.
Samarium
present
What it does
Samarium-cobalt magnets, for where it runs too hot for neodymium. On China’s April 2025 licence list.
China
Export licence since April 2025, including samarium-cobalt magnets.
Terbium
squeezed now
What it does
Added to magnets, with dysprosium, so they keep their strength when hot.
~$1,200 (before Apr 2025)→to$6,745 (Sep 2026)
what moved it: export controls
Before AI
A tiny market serving electric-car motors, wind turbines and hard drives. Japan was the biggest buyer outside China.
What changed
Not AI. China’s licences in April 2025, then the cut-off to Japan in January 2026, which sent Japanese buyers into the small pool in Europe and America.
The squeeze
Under Chinese export licence since April 2025. By September 2026 the European price of terbium oxide was $6,745 a kilogram.
- Who supplies
- China (about 91% of refining)LynasMP Materials
- Who buys
- Japanese magnet makersWestern DigitalSeagateNidecABB
- Who is working on it
- LynasMP MaterialsNoveon MagneticsWestern Digital + Microsoft (recycling)
The bet
See dysprosium.
China
Export licence since April 2025, including magnets that contain it.
Dysprosium
squeezed now
What it does
Added to magnets so they keep their strength when hot. In the motors of hard drives, fans and pumps.
~$280 (before Apr 2025)→to$3,500 (Sep 2026)
what moved it: export controls
Before AI
A tiny market serving electric-car motors, wind turbines and hard drives. Japan was the biggest buyer outside China.
What changed
Not AI. China’s licences in April 2025, then the cut-off to Japan in January 2026. AI adds pumps, fans and drives on top of a market that was already broken.
The squeeze
Under Chinese export licence since April 2025. By September 2026 dysprosium oxide in Europe cost about 16 times the Chinese domestic price. Grain-boundary diffusion, the technique that cuts how much you need, has one equipment supplier outside China.
- Who supplies
- China (about 91% of refining)LynasMP Materials
- Who buys
- Japanese magnet makersWestern DigitalSeagateNidecABB
- Who is working on it
- LynasMP MaterialsNoveon MagneticsWestern Digital + Microsoft (recycling)
The bet
Recovery from retired hard drives (Western Digital and Microsoft run a programme) and heavy-rare-earth separation outside China. A wider control package is suspended until November 2026.
China
Export licence since April 2025, including magnets that contain it.
Erbium
present
What it does
Erbium-doped fibre amplifies the signal on long links between campuses. The pump lasers that drive it are, per Lumentum, even tighter than the main lasers.
China
Added in the October 2025 package, which is suspended until November 2026.
Hafnium
load-bearing
What it does
Hafnium oxide, a few atoms thick, insulates the gate of every advanced transistor made since 2007.
The squeeze
It is only produced as a by-product of purifying zirconium. I have not sourced current supply figures.
Tantalum
squeezed now
What it does
Tantalum capacitors feed a GPU hundreds of amps within microseconds. An AI server carries two to three thousand of them, against a few dozen in an ordinary server. Also the barrier around copper wiring.
~$55 (2024 low)→to$115 (Jan 2026)
what moved it: AI servers, plus a mine collapse
Before AI
About 2,500 tonnes a year into capacitors for phones, cars and aerospace. AI data centres took essentially none of it in 2021.
What changed
By late 2025 AI data centres took an estimated 8 to 12% of production, heading for 15 to 18%. TrendForce puts AI demand growth at 62% a year.
The squeeze
The Democratic Republic of the Congo mines 51% of about 2,500 tonnes a year, and the Rubaya mine was halted by a collapse in January 2026. Ingot prices went from RMB 2,600 to 6,650 a kilogram this year. KEMET raised prices three times in twelve months, some lead times reached 40 to 52 weeks, and hyperscalers have reportedly locked up over 70% of high-end capacity.
- Who supplies
- Congo and Rwanda minesOrient TantalumCabotTaniobisKEMET (Yageo)Kyocera AVXVishayPanasonic
- Who buys
- MicrosoftGoogleAmazonMetaServer makersCar makers
- Who is working on it
- Chinese polymer-tantalum makers (volume from 2027–28)
The bet
Under 1% of the bill of materials, and it can stop a finished server leaving the factory. The scarce step is ultra-high-capacitance tantalum powder, and qualifying a new supplier takes one to two years. A dissent: TTI’s tracking showed lead times of 16 to 18 weeks in January, tight but orderly.
Tungsten
squeezed now
What it does
The plugs that carry signals up out of the transistor, and the word lines in memory.
~$30 (five-year average)→to$340 (Jul 2026)
what moved it: export controls and defence
Before AI
About 162 thousand tonnes a year, two-thirds of it into cutting tools. China mined about 80% and refined 85%.
What changed
Chips are a small buyer: tungsten hexafluoride gas for memory. The larger new demand is wire for slicing solar wafers (now 14% of the market) and a US rule barring Chinese tungsten from defence contracts from January 2027.
The squeeze
The benchmark price went from $83 to $340 a kilogram between January and July 2026. Under Chinese licence since February 2025, with 15 authorised exporters.
- Who supplies
- ChinaAlmonty (Sangdong, Korea)EQ ResourcesTungsten West (Hemerdon)Global Tungsten & Powders
- Who buys
- ToolmakersDefence contractorsSamsungSK hynix
- Who is working on it
- Almonty (oxide plant, 2028)Lam Research (molybdenum instead)
The bet
Inside the chip, molybdenum is the named successor, so chip demand for tungsten is a slowly melting block. The price is a defence and tooling story more than an AI one.
China
Export licence since February 2025, through 15 authorised exporters.
Platinum
a newer bet
What it does
An iron-platinum alloy is the recording layer in HAMR hard drives, the technology displacing ruthenium-based media.
what moved it: not a price story
Before AI
Hard-drive media used a ruthenium spacer under a cobalt-chromium-platinum layer.
What changed
HAMR drives record on iron-platinum. Seagate expects about half its 2026 capacity on HAMR; Western Digital follows in 2027.
- Who supplies
- South African platinum miners
- Who buys
- SeagateWestern Digital
The bet
The other side of the ruthenium trade. Hard drives still store an exabyte for about $25M against about $500M on flash, so bulk AI storage stays on spinning disks.
Gold
load-bearing
What it does
Connector plating and wire bonds: the contact that does not corrode.
Lead
present
What it does
Lead-acid batteries ran data-centre backup for decades. Lithium iron phosphate is replacing them.
Bismuth
present
What it does
With tellurium, the thermoelectric coolers that keep transceiver lasers on wavelength. On China’s February 2025 licence list.
China
Export licence since February 2025.
Uranium
squeezed now
What it does
Fuel for the only firm, carbon-free power a hyperscaler can sign for today.
~$50 (for years)→to$101 (Jan 2026 peak)
what moved it: reactor restarts, with AI deals on top
Before AI
Reactors needed about 69,000 tonnes a year and mines dug 60,000; old stockpiles covered the gap. Utilities under-bought for thirteen years running.
What changed
The World Nuclear Association sees requirements near 150,000 tonnes by 2040, a forecast drawn before most of the AI deals. Hyperscalers have since contracted about 8.5 GW of existing reactors.
The squeeze
Mines supplied about 90% of what reactors used in 2024. Kazakhstan mines 39%. Spot passed $101 a pound in January 2026. Advanced reactors need a higher-enriched fuel, HALEU, which has no commercial US source; Centrus’s new capacity is due by 2029.
- Who supplies
- KazatompromCanadaNamibiaUrencoOranoRosatomCentrusConstellationTalenVistra
- Who buys
- MetaAmazonGoogleMicrosoft
- Who is working on it
- Centrus (HALEU, 2029)TerraPowerX-energyKairos PowerOkloRadiant
The bet
Hyperscalers have about 8.5 GW of existing US reactors under contract and 45 GW of conditional small-reactor agreements, but exactly one data-centre reactor, of 50 MW, is under construction. Carnegie’s audit: every announced deal together covers under 20% of projected demand. The fuel chain, enrichment above all, is the part with both a schedule and a shortage.
What the table says
The scarce thing is a form, not an element. Silicon is sand, and it is yellow anyway, because one Japanese company makes about 90% of the glass cloth that keeps a large chip package flat.Tom’s Hardware on the T-glass shortage. Nittobo’s new capacity arrives in mid-2027. Indium is not rare; a qualified six-inch indium phosphide wafer is. Iron is the fourth most common element in the crust, and a transformer core made of it has a two-to-three-year queue. In every yellow cell the shortage sits at one factory step where qualification takes years and money does not shorten it.
By-products cannot answer a price. Gallium comes out of alumina refining. Indium and germanium come out of zinc. Ruthenium comes out of platinum mining, tellurium out of copper, hafnium out of zirconium, helium out of liquefied natural gas. Nobody opens a zinc mine to sell more indium. So when AI demand arrives, the price moves a long way and the supply barely moves at all: ruthenium tripled in a year.Reuters, March 2026: about $560 to $1,750 an ounce.
The cheapest parts have a veto. Helium is about $6 of an $18,000 wafer. The tantalum capacitors in an AI server are under 1% of its cost, and without them a finished machine sits on the line. Copper is under half a percent of a data centre. Buyers this insensitive to price do not negotiate. They prepay.
Not every squeeze is AI’s doing. Each yellow cell now says what actually moved its price, and for about half of them the answer is not AI. Gallium, yttrium, tungsten, dysprosium and terbium moved because Beijing required a licence. Helium moved because of a war. The cells where AI itself is the buyer that broke the market are fewer: indium, ruthenium, tantalum, the glass cloth, and copper at the margin. That matters for a bet, because a policy squeeze can end with a signature and a demand squeeze cannot.
Follow the prepayment. It marks the bottleneck more reliably than the price does.
That last point is the most useful one on the page. Nvidia put $2 billion each into Lumentum and Coherent for lasers, and up to $3.2 billion into Corning for fibre. Meta committed up to $6 billion to Corning. And on the day this was written, Lumentum itself put down $87 million to reserve indium phosphide wafers from AXT through 2031.Shanghai Metals Market, 6 October 2026. Each cheque lands one layer further upstream than the last.
Where I would look
Four kinds of bet fall out of the table. I have ordered them by how crowded I think they are, least crowded last.
- One layer upstream of the last big cheque. The lasers are spoken for, so look at substrates and the tools for new laser lines. Fibre is spoken for, so look at preforms and germanium. Capacitors are locked up, so look at the tantalum powder. This is the most legible trade and the most watched.
- Substitution. Molybdenum for tungsten, aluminium for copper, iron-platinum for ruthenium, lithium niobate for silicon modulators, diamond for copper heat spreaders, a PFAS-free fluid for the old coolants. These are the blue cells. In most of them the value goes to whoever makes the tool or the process, not to whoever owns the metal.
- Reclaim. Neon was a crisis in 2022 and is nearly a non-story now, mostly because of recycling. Helium recovery, rare earths from retired hard drives and germanium from scrap fibre are the same idea at an earlier stage.
- Refining outside China. Gallium, the heavy rare earths, yttrium. The ore exists elsewhere; the refineries do not. This is slow, capital-heavy and dependent on governments, which is why it is uncrowded.
One date sits over the whole right-hand side of the table. China’s suspension of its tightest controls, including the ban on gallium, germanium and antimony exports to the United States, runs out on 27 November 2026. If it is not renewed, the controls come back by default. Here is what that touches.The lanthanides.io tracker lists every announcement. The licensing regime underneath never went away, and exports to Japan have been cut off since January.
What would make this wrong
AI is the marginal buyer of nearly everything in yellow, which is why these prices moved. It also means a pause in AI spending removes exactly the demand that is setting them. Kpler makes this argument about copper and it applies down the list.Kpler, July 2026. Data-centre construction is under 2% of copper demand and about all of this year’s growth.
Chokepoints also get fixed, usually in two to four years, usually by process change and not by new mines. Several of the yellow cells have a credible dissent attached: LightCounting expected the laser shortage to ease by the end of 2026, and one long-running tracker of tantalum lead times showed them tight but orderly in January. I have put those inside the relevant cells.
And the November deadline may simply be extended, as it was last year.
What I have not checked
The transformer numbers come from secondary write-ups of a Wood Mackenzie survey I have not read. Funding and performance figures for the start-ups are the companies’ own. Entries marked “textbook chemistry” have no reporting behind them. A grey cell means I found no role, not that there is none, and I expect to be corrected on a few. This is a map of where the constraints are, not advice about what to buy.