BlackRock announced that its AUM surpassed $6 trillion during its fourth-quarter 2017 earnings call last week. The asset manager's iShares exchange-traded fund business made up about 28% of those holdings, up from 25% at the end of 2016 and 22% at the end of 2014. In terms of net client flows, iShares has supported much of the firm's organic growth. More than half of total net new assets during 2017 were inflows into iShares ETFs; while fourth-quarter breakouts were even among ETFs, institutional assets and cash management assets, the trailing three quarters were heavily weighted toward the ETFs.
