Mark Cuban became a billionaire in 1999 when he sold his company, Broadcast.com, to Yahoo for $US6 billion.
His net worth is now estimated at $US3 billion, and he has numerous mansions, private planes, and sports cars to his name.
He also owns the Dallas Mavericks, who brought the NBA championship home in 2011.
“I’m the luckiest guy in the world,” Cuban said at Business Insider’s IGNITION conference. “I only have to do what I want to do. I only have to do what I like to do.”