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.

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 .

Trade Desk (TTD) stock is surging on news that the company will join the S&P 500 (^GSPC), replacing Ansys (ANSS). Robinhood (HOOD) and Applovin (APP) are trading slightly lower after not making the cut to join the index once again.

Shares of the rare-earth miner have rocketed to record highs in almost no time in a story that include the Defense Department and Apple.

Detailed price information for MP Materials Corp (MP-N) from The Globe and Mail including charting and trades.

Rare-earth firm MP Materials (MP) stock is skyrocketing after the company announced a deal for the US Department of Defense to buy $400 million of company shares. The Pentagon will be the company's largest shareholder as part of the US government's efforts to reduce China's rare earth metal dominance.

An Historic Public-Private Partnership The U.S. Defense Dept. announced yesterday it was making a multibillion-dollar investment in MP Materials (NYSE:MP), the sole operator of the rare earth mineral mine in California.

Why investors are selling MP stock today Let's put the tariffs question to the side for a moment, and focus on the rare earths aspect -- and what it means for MP Materials stock.