The billionaire philanthropist testified on Wednesday in a closed-door congressional hearing about the Justice Department’s investigation of Jeffrey Epstein.

© Pete Marovich for The New York Times

Antonio Gracias, an investor who has built a $65 billion stake in the company, exemplifies the economic upside of being Mr. Musk’s ally.

© Jim Vondruska for The New York Times

While Elon Musk may soon become a trillionaire, his rocket company’s market debut is set to the change the lives of its current and former employees, too.

© Chelsea Beck