2. Elon Musk Invests His Paypal Earnings on Tesla Motors

Founder of PayPal, Elon Musk sold his startup to eBay in 2002 for $1.5 billion. He took the earnings from that sale and put the money into his own startups: Space Exploration Company SpaceX and Tesla, which was almost out of cash. This later led to Musk running out of cash. If Tesla had failed, Musk would have been totally broke.

1. Facebook Turns Down Yahoo's $1 Billion and Microsoft's $15 Billion

Just two years after Mark Zuckerberg founded Facebook from his dorm room, Yahoo offered $1 billion to buy it. Zuckerberg rejected the offer telling the Wall Street Journal "There is so much more to do here”. One year later, in 2007, Microsoft CEO Steve Ballmer offered Zuckerberg $15 billion to hand over Facebook, according to David Kirkpatrick's The Facebook Effect. Zuckerberg declined again. Now, the social network is valued around $100 billion, and after the IPO, Zuckerberg alone became more valuable than the Microsoft's offer.