With $6.3 trillion under management, BlackRock remains unchallenged as America's largest asset manager in the 2018 edition of the II300.

The 15th annual ranking of the 300 largest asset managers based in the U.S. repeats last year's top three of BlackRock, Vanguard Group, and State Street Global Advisors. Combined, the three firms accounted for over $14 trillion of assets under management.

The II300 is powered by eVestment and supplemented by information provided by the asset managers to Institutional Investor.