No. 6: BlackRock
Total mutual fund assets: $494.7 billion
Long-term assets: $233.9 billion
Morningstar tracks 142 Blackrock open-end mutual funds, the largest being the $39.2 billion BlackRock Global Allocation (MALOX). But in the fund world, BlackRock is noted for its iShares exchange-traded funds, headed by the $125.9 billion iShares Core S&P 500 ETF (IVV).