Not content to focus just on SpaceX and Tesla, Musk also chairs solar energy provider SolarCity (, which was founded in 2006 by his cousins, brothers Lyndon and Peter Rive. SolarCity )debuted on the Nasdaq in December at $8 a share and has since risen to $38, further swelling the fortune of Musk, its largest shareholder.
SolarCity offers solar power for homes and businesses, designing and installing custom-built systems. The company is still losing money but remains expanding, reporting last week that its customer base had grown to nearly 65,000.
Elon Musk unveiled designs for the Hyperloop Monday, a superfast tubular transport system promising travel from L.A. to San Francisco in 30 minutes.