Shares in the materials sector declined alongside major indexes.

Hertha Metals, a steel startup planning to produce high-purity iron for U.S.-made rare-earth magnets-essential to F-35 jet fighters and missile-guidance systems-has closed a $133.65 million Series A round that includes a $65 million equity investment from the U.S. government, its chief executive officer said. The financing comes amid the Trump administration's multibillion-dollar campaign to loosen China's stranglehold on minerals vital to U.S. defense and advanced technologies.