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. Shares of MP Materials fell 5.8% in extended trade.

MP Materials launched a $500M public offering of common stock, and expects to grant a 30-day underwriters option to purchase up to an additional 15% of shares to be sold in the offering.

In a decisive action to bolster the U.S. supply chain for rare earth magnets—essential elements for fighter jets, missiles, and electric vehicles—the

MP Materials shares are trading lower in after-hours Wednesday after the company announced a proposed public offering.

MP Materials has a large amount of cash at hand and strong demand for rare earth magnets, with new partnerships announced. Read why I'm rating MP stock a buy.

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.

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

Johnson & Johnson (JNJ) shares tick higher in pre-market trading after the company raised its full-year earnings and sales guidance, though looming pharmaceutical tariffs from President Trump remain a key risk for the sector.