Promethium is not an investable "rare earth commodity" in any normal sense. Commercial promethium is mostly promethium-147 sold as a radioisotope product into regulated industrial uses. Investable exposure is almost always indirect through radioisotope production, sealed-source, and instrument ecosystems.
Pm-147 is a programmatic, regulated radioisotope with limited, capacity-bound supply and thin commercial transparency, so you cannot get clean "Pm price exposure" the way you can with exchange-traded metals.
DOE's National Isotope Development Center describes Pm-147 as a new product being supplied via extraction from a plutonium waste stream and planned/ongoing irradiation of Nd-146 in HFIR. That is your "ore body": reactor and hot-cell capacity.
DOE's FY2026 request for Isotope R&D and Production explicitly mentions increasing production of promethium-147. That is the closest thing you get to a forward supply signal in this market.
ORNL has described harvesting Pm-147 from Pu-238 production leftovers and improving purity and shipment cadence. Translation: if the hot-cell workflow and separation trains improve, more material can reach customers.
One of the most practical uses of Pm-147 is thickness/basis-weight gauging for thin materials. When industrial lines upgrade and measurement systems refresh, demand for gauges and sources can rise.
Pm-147 is historically tied to betavoltaics (the Betacel used Pm-147). Modern activity often focuses on alternative isotopes (Ni-63, tritium), but Pm-147 still appears in R&D and some company roadmaps. This tends to create headline bursts more than stable bulk demand.
Promethium is usually deployed as a sealed source. That bakes licensing, transport, and end-of-life obligations into adoption and total cost of ownership. This is why substitution into non-nuclear sensors is structurally attractive in some gauging markets.
This is the closest conceptual exposure, but it is messy:
Much of the Pm-147 story sits inside DOE/ORNL program execution and national lab capabilities (not a pure public equity).
The investable angle is usually through companies that build, operate, or supply the broader nuclear services, hot-cell, and isotope handling ecosystem, or through firms that benefit from expanded isotope program activity.
Your due diligence question here is simple: does the company actually touch isotope production/processing or just "nuclear" generally? DOE's own program framing is a helpful reality check.
If thickness gauging is a key use case, then the companies selling the gauges and web measurement systems are a cleaner, more investable path than chasing the isotope itself.
Important nuance: many of these OEMs can also sell non-nuclear alternatives, which can reduce sensitivity to Pm-147 availability (good for stability, bad if you want "promethium upside").
This is where the "promethium narrative" gets loud, but investability is often limited:
Treat this as venture-style risk: technical milestones, regulatory acceptance, and manufacturing pathways matter more than isotope headlines.
Pm-147 is sold in millicurie units under controlled channels, often as special order, and it is regulated. This is not "buy a metal, store it, sell it later."
No. It is mostly an isotope (Pm-147) supplied through national-lab-style production and regulated distribution, not a mined bulk commodity.
Usually via industrial gauging and measurement OEMs (because that is a real demand anchor) or via broader nuclear services and isotope ecosystem exposure, if a company can prove it participates in that chain.
Assuming "promethium demand" scales like an energy-transition metal. In reality, it is constrained by reactor and radiochemistry capacity, regulated lifecycles, and viable substitutes in many applications.