Japan is Just “Months” Away From Running Out of a Critical Rare Earth Mineral. Here’s Why Rare Earths are Becoming AI’s Biggest Bottleneck.

Japan has told Washington it is “months” from running out of yttrium, a rare earth used in jet engines and chipmaking equipment, and has asked the US to help push China to ease its export restrictions. The Financial Times reported the warning first on October 20, 2026. Kalshi posted on X on October 20, 2026: “JUST IN: Japan says it is “months” from running out of yttrium and asks the US to help push China to ease rare earth curbs”. On October 21, China defended its restrictions on Japan and cited concerns about Japanese “remilitarization.”

US rare earth stocks barely moved. In early trading on October 21, MP Materials (NYSE:MP) rose 1.11% to $39.48. USA Rare Earth (NASDAQ:USAR) gained 1.29% to $10.19, and Energy Fuels (NYSEAMERICAN:UUUU) added 2.13% to $8.39. Over the past month, the three had fallen 16.46%, 33.7% and 28.29%.

What Japan’s Warning Actually Covers

So far, Japan has only described a shortage and made a request. No US commitment, deal or timeline has been announced.

Yttrium goes into heat-resistant coatings on jet-engine parts, into electronics, and into semiconductor manufacturing equipment, so it feeds directly into the AI chip expansion. The US Geological Survey estimates that 2025 global mine production was 10,000 to 15,000 tonnes of yttrium oxide equivalent, and China produced most of it. The US has no fully commercial plant to separate yttrium (split mixed ore into individual elements) or refine it (purify it to usable grade). US yttrium oxide imports fell to zero in May and June 2026. Reuters then reported that 29 tonnes more were approved for July.

China has done this before. It restricted shipments to Japan in 2010, tightened its restrictions in early 2026 and stopped key exports to Japan in July 2026. The US and China discussed a truce in May 2026, but the restrictions kept biting.

Which Stocks Are Impacted

MP Materials: It runs the Mountain Pass mine and sells NdPr oxide and metal (the main magnet feedstock) plus gadolinium. It also makes magnets in Fort Worth. Second-quarter revenue rose 89% to $108.49 million. Its first heavy rare earth separation circuit remains on track to produce terbium and dysprosium later this year. Management has called yttrium only a potential opportunity. MP has announced no yttrium revenue.

USA Rare Earth: This is the speculative name. Second-quarter revenue was $5.82 million, missing expectations. It owns the Round Top heavy rare earth deposit in Texas, a magnet plant in Stillwater, Oklahoma, and Less Common Metals in the UK. It is also buying Serra Verde for about $2.8 billion. We could not verify any yttrium production.

Energy Fuels: It is mainly a uranium miner. Its White Mesa Mill in Utah produces NdPr oxide and has made high-purity terbium and dysprosium. We could not verify any yttrium production.

Why the Market Shrugged

All three companies are built around magnets, and MP’s chief executive said in August that “the vast majority of demand is no-heavy.” A yttrium shortage hits Japanese aerospace and chip-tool supply chains before it reaches US magnet economics.

The long-term demand case is stronger. Magnets power the motors and actuators in humanoid robots and EVs, as well as data center cooling and power equipment (the same picks-and-shovels angle behind the AI expansion we mapped in a free report on seven suppliers powering AI infrastructure). He added that “30 million or 40 million humanoid robots a year” would use up “100% of rare earth magnet production globally, including China.” New supply from African and friendly projects, however, takes years to reach production and pass customer approval. A shortage measured in months will not wait for it.

Does Japan’s Yttrium Crunch Change the Case for These Stocks?

Not in the near term. The warning shows how much power China holds, but it adds no revenue to any of these three companies. MP remains the only one with revenue at scale and a working heavy rare earth circuit. USA Rare Earth stays a development-stage story.

There are four milestones to watch. First, whether China eases its restrictions on Japan before year-end. Second, whether US yttrium oxide imports resume beyond the 29 tonnes Reuters reported for July. Third, whether MP reports its first dysprosium and terbium output by December 31, 2026. Fourth, whether USA Rare Earth reaches 600 MTPA run-rate capacity at Stillwater in Q4 2026.

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