Here's Why MP Materials Stock Slumped in December (And Why It's Surging in 2026)

Shares in MP Materials (NYSE: MP) have experienced a volatile ride over the past few months. They declined by 18.5% in December according to data provided by S&P Global Market Intelligence, only to rise by 23.7% in 2026 as I write. What's going on and what can investors expect in the future?

MP Materials stock ups and downs

Rare-earth materials took a hit in October after China agreed to a one-year delay in imposing restrictions on rare-earth exports to the U.S. While that's a positive for the U.S. on the whole, it serves to reduce the clamor for urgent action to secure a domestic supply of rare-earth materials and magnets critical to the modern economy.

MP Materials has been a major beneficiary of that trend with a transformative public-private partnership deal signed with the Department of Defense in July. A few days later, MP Materials signed a $500 million partnership with Apple.

As such, investors often treat the stock as a proxy for geopolitical events relating to rare-earth materials and magnets. When trade tensions flare up, the market starts pricing in MP Materials as the solution to the problem, and when they ease, investors start remembering that the company has plenty of risk embedded in it. Those risks include political risk (the U.S. government owns a stake in MP Materials), potential regulatory hurdles from future U.S. administrations, execution risk associated with the construction of its new "10X Facility", and the need for future funding.

Image source: Getty Images.

The easing of trade tensions with China (a country that controls 90% of global rare-earth magnet production) through the last quarter of the year caused share price weakness, resulting in an 18.5% decrease in the stock price in December.

Venezuela and MP Materials in 2026

That said, rare-earths might be rare, but they are rarely out of the headlines, particularly when it comes to geopolitical events. That point came home to roost after recent events in Venezuela, where the market is now pricing in the possibility of better trading relations with Venezuela, a country rich in resources, including rare-earth materials in the Orinoco Mining Arc.

That could be good news for MP Materials, as it not only has the Mountain Pass rare-earth deposit in California but also operates a magnet production facility in Texas and plans to build and open the "10X Facility" in 2028.

Image source: Getty Images.

As such, it could potentially supply these facilities with rare-earth materials from Venezuela, particularly if they include heavy rare-earth elements like Dysprosium (Dy) and Terbium (Tb), which Mountain Pass lacks compared to Venezuelan rare-earth deposits, which are believed to be abundant.

Consequently, investors can expect the speculative rollercoaster to continue in 2026, as it's far from clear where trade relations with China are headed, let alone with Venezuela.

Lee Samaha has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Apple. The Motley Fool recommends MP Materials. The Motley Fool has a disclosure policy.