MP Materials Corp. (MP) saw its stock price plummet 5.03% during intraday trading on Wednesday, reflecting significant market pressure on the rare earths producer.

The sharp decline followed news that U.S. Vice President JD Vance proposed establishing a preferential trade bloc for critical minerals, featuring coordinated price floors. This policy shift aims to counter China's dominance in the sector but raised concerns about potential constraints on profitability for companies like MP Materials, as government-mandated price floors could limit pricing power and market flexibility.

The announcement was made at a Washington meeting attended by over 50 countries, part of a broader U.S. effort to diversify critical minerals supply chains. Market participants reacted negatively, interpreting the move as a step away from previous company-specific agreements, such as one MP Materials had with the administration, towards a more regulated international framework that may impact future earnings.