The “psychologically astute” Larry Fink, photographed at BlackRock headquarters in February.

Considering the enormous power he is believed to wield, it’s remarkable how few people have heard of Larry Fink. In political and business circles—among the men who travel the now well-worn corridor between Washington and Wall Street—Fink, the chairman and C.E.O. of BlackRock, the giant asset-management firm, is described as possibly the most important man in finance today. But mention his name to most people and they draw a blank. Despite his considerable wealth, he is virtually unknown on the society circuit in Manhattan, where he has an apartment on the Upper East Side, or in Aspen, where he also has a home. In North Salem, the affluent enclave north of New York City where he and Lori, his wife of 35 years, have a 26-acre farm, he is perhaps slightly better known, if only because a number of Wall Street bankers have estates there. But still—just a few months ago—when one of his neighbors, a prominent New York agent, furious that a popular horse path through the Fink estate had been blocked off, was told who owned the property, her response was: “Who is Larry Fink?”

Yet among the men who run Wall Street, it would be hard to find anyone who is not at least a little bit in awe of Larry Fink. While some—especially those who have known him the longest—snicker privately about how clearly the 57-year-old seems to relish his “transformation” in the last year and a half “into a Wall Street statesman,” its top consigliere, and the leading member of the country’s financial oligarchy, there is nothing but admiration for the vast power of BlackRock. In December, when Fink’s $13.5 billion acquisition of Barclays Global Investors was finalized, BlackRock, the company he founded 22 years ago, officially became the largest money-management firm in the world. A global colossus—with $3.3 trillion in assets under its direct management and another $9 trillion it supports—BlackRock manages about $1 trillion of pension and retirement funds for millions of Americans and oversees the investments of scores of institutions around the world: from state and local governments to college endowments, from Fortune 500 companies to the sovereign-wealth funds of, among others, Abu Dhabi and Singapore.

BlackRock’s vast reach in the global markets is not, however, its only source of influence these days. That Fink pulled off the Barclays deal in the aftermath of 2008’s financial meltdown is, in itself, impressive, but he did more than merely survive the wreckage unscathed. Indeed, it is hard to argue that anyone, or any firm on Wall Street, gained as much stature from the economic crisis as did Fink and BlackRock. At the height of the disaster, when the American economy was on the brink, it was to Fink that Wall Street’s C.E.O.’s—including J. P. Morgan Chase’s Jamie Dimon, Morgan Stanley’s John Mack, and A.I.G.’s Robert Willumstad—turned for help and counsel. As did the U.S. Treasury and the Federal Reserve Bank of New York, whose top officials turned to Fink for advice on the financial markets and assistance on the $30 billion financing of the sale of Bear Stearns to J. P. Morgan, the $180 billion bailout of A.I.G., the $45 billion rescue of Citigroup, and those of Fannie Mae and Freddie Mac at $112 billion and growing.

Today, through an array of government contracts, BlackRock has effectively become the leading manager of Washington’s bailout of Wall Street. The firm oversees the $130 billion of toxic assets that the U.S. government took on as part of the Bear Stearns sale and the rescue of A.I.G.; it also monitors the balance sheets of Fannie Mae and Freddie Mac—which together amount to some $5 trillion—and provides daily risk evaluations to the New York Fed on the $1.2 trillion worth of mortgage-backed securities it has purchased in an effort to jump-start the country’s housing market.