You Have To Work Like Someone Is Trying To Take It All Away From You. MARK CUBAN. Outwork Everyone. Brutally Honest Business Advice. . Mark Cuban is an American businessman and investor with a net worth of over 4 billion dollars. He is the owner of the NBA’s Dallas Mavericks, co-owner of 2929 Entertainment and chairman of AXS TV. He is also one of the main shark investors on the ABC reality television series, Shark Tank.