1. Elon Musk: $297bn
Musk is the CEO of Tesla and the founder and CEO of SpaceX. He divides his time between SpaceX, Tesla and projects like Hyperloop, a proposed ultra-high-speed train line.
2. Jeff Bezos: $201.7bn
The former hedge fund manager started Amazon in his garage in 1994. Bezos has invested heavily in space technology too, and also owns The Washington Post newspaper. After stepping down as Amazon CEO he took on the new role of executive chair.
