Larry Fink is one of the most powerful players in global finance. The 63-year-old former securities trader cofounded and still runs the world’s biggest money-management firm, BlackRock, which controls assets approaching $5 trillion. And he’s on HBR’s 2015 list of the world’s top-performing CEOs. But what truly sets Fink apart is his desire to change the very financial system that made him who he is.

A version of this article appeared in the November 2015 issue (pp.120–125) of Harvard Business Review.