The US Department of Defense (DoD) will become the largest shareholder in MP Materials (NYSE:MP) after agreeing to purchase US$400 million worth of preferred stock in the company, which owns and operates the only rare earth mine in the United States.

The rare earths producer said the proceeds from the investment will fund the expansion of its processing capabilities at the Mountain Pass mine in California and support the construction of a second magnet manufacturing facility in the US.

The materials mined and processed by MP are critical to the production of permanent magnets used in military systems, including the F-35 fighter jet, drones, and submarines.

The US has depended heavily on foreign imports for these materials — primarily from China, which accounted for about 70 percent of rare earth imports in 2023, according to the US Geological Survey.

In a press release issued Thursday (July 10), MP Materials described the agreement as a ‘transformational public-private partnership’ and said it would ‘dramatically accelerate the build-out of an end-to-end US rare earth magnet supply chain and reduce foreign dependency.’

The investment gives the Pentagon newly created preferred stock convertible into common shares, along with a 10-year warrant to buy additional stock at US$30.03 per share.

If fully converted and exercised, the DoD would own 15 percent of MP Materials, based on current share counts as of July 9. That would exceed the 8.61 percent stake held by CEO James Litinsky and the 8.27 percent stake held by BlackRock Fund Advisors.

Litinsky emphasized that the deal does not equate to government control of the company. “This is not a nationalization,” he said in an interview on CNBC. “We remain a thriving public company. We now have a great new partner in our economically largest shareholder, DoD, but we still control our company. We control our destiny. We’re shareholder driven.”

MP’s new magnet facility, called the “10X Facility,” will increase the company’s magnet manufacturing capacity to 10,000 metric tons annually once it begins commissioning in 2028. The exact location of the facility has not yet been disclosed.

The Pentagon has committed to purchasing 100 percent of the magnets produced at the 10X Facility for 10 years.

Additionally, the DoD will guarantee a minimum price of US$110 per kilogram for MP’s neodymium-praseodymium oxide (NdPr), a key material used in magnet production. If market prices fall below that threshold, the Pentagon will pay the difference quarterly.

In return, once the new facility is operational, the government will receive 30 percent of any upside above US$110 per kilogram.

To further support the buildout, MP Materials expects to receive a US$150 million loan from the Pentagon within 30 days to expand its heavy rare earth separation capabilities at Mountain Pass, the only active rare earth mine in the US.

It is also commissioning a magnetics facility in Texas, known as Independence, to bolster its downstream processing capabilities.

As the only domestic miner with vertically integrated capabilities and a clear path to rare earth magnet production at scale, MP Materials now sits at the center of the Biden-to-Trump era effort to bring critical mineral supply chains back to American soil.

Securities Disclosure: I, Giann Liguid, hold no direct investment interest in any company mentioned in this article.