MP Materials shares remain in focus after soaring 20% yesterday on news that Apple plans to invest $500 million in the rare earths firm, news that came just days after the Department of Defense took a stake in the company.

MP Materials said on Wednesday it would sell $500 million of its common stock, a day after the U.S. rare earths miner inked a supply deal with Apple .

MP Materials Corp., a rare earth materials company, is seeing its stock price rise on news of a major commitment from tech giant Apple.

After nearly doubling in value over the last week and closing at a record high Wednesday, shares of MP Materials are sinking premarket Thursday after the rare earths miner announced plans to sell new stock.

However, it’s not just the government rushing to ensure rare earth supply. Apple (NASDAQ: AAPL) has one-upped the Pentagon by announcing a $500 million agreement with MP Materials to secure recycled rare earth magnets.

The Cupertino tech giant has inked a $500 million deal with Mountain Pass’ owner and operator MP Materials, the two companies announced on Tuesday, in a move that will help Apple onshore a part of its sprawling supply chain.

MP Materials, which has the only operational rare earths mine in the U.S., has drawn interest as a challenger to China's dominance from investors ranging from the Pentagon to tech giant Apple in recent days.