Apple is investing $500 million in the mining company MP Materials to secure a domestic supply of rare earth magnets for its devices.

Shares of MP Materials Corp. were up nearly 25% and headed for a new high on Tuesday after the rare-earths producer struck a deal with a major, notable partner — the latest sign that U.S. tech compani...

MP will supply Apple with magnets that it produces in a Texas facility, and use recycled materials processed at a site MP will build in California.