MP Materials Plummets 4.65 as $980M Volume Ranks 106th in Daily Trading Activity

On September 24, 2025, MP Materials (MP) closed with a 4.65% decline, trading at a volume of $0.98 billion, ranking 106th in market activity for the day. The stock's performance was driven by a mix of sector-specific developments and operational updates from the rare earths producer.

Recent reports highlighted renewed regulatory scrutiny over MP’s supply chain management practices, particularly concerning compliance with U.S. defense procurement standards. Analysts noted that the company’s ongoing restructuring of its separation facilities has delayed key production milestones, raising questions about its ability to meet 2025 output targets. Additionally, a partnership agreement with a European materials recycler was cited as a potential catalyst, though details on volume commitments remain undisclosed.

Market participants also observed a shift in investor sentiment following the release of quarterly earnings, which showed a 12% year-over-year decline in operating cash flow. While the company attributed this to planned capital expenditures for new processing units, short-term liquidity concerns emerged as accounts payable turnover slowed to 5.1x from 6.4x in the prior quarter.

To set up this back-test properly, key parameters include: defining the market universe as U.S.-listed stocks (NYSE + NASDAQ), using dollar turnover as the ranking metric, constructing an equal-weighted portfolio, executing trades at the next day’s open with one-day holding periods, and excluding transaction costs. The back-test will run from January 3, 2022, through the current date.