Who are the sharks? They're self made millionaire and billionaire investors who are entrepreneurs themselves. Kevin O'Leary is a venture capitalist who turned a ten thousand dollar loan into a software business worth 4.2 billion dollars. Barbara Corcoran went from working as a waitress in Manhattan to building the city's pre-eminent real estate empire. Daymond John is a fashion and branding expert, who grew his homegrown clothing line into the globally recognized fashion brand, Fubu. Robert Herjavec, the son of an immigrant factory worker, is now a technology mogul, who sold his first internet companies for over 350 million dollars. And Mark Cuban, notorious billionaire entrepreneur, and the outspoken owner of the Dallas Mavericks.