3. Elon Musk
Elon Musk has been working to revolutionize transportation, both in space and on Earth. Musk made his original fortune after founding and selling PayPal, an online payment processing service. He is now the CEO of Tesla, an electric car company in which he has a 21% ownership stake. He also owns SpaceX, a space exploration company actively working towards putting humans on Mars. He is involved in a variety of other companies in addition to his main ventures, bringing his total net worth to $179.9 billion.
