The head of BlackRock's $2 trillion ETF-investing business told us the 3 biggest growth opportunities on his radar — and explained how to start taking advantage of them now

· Exchange-traded funds helped investors navigate the recent period of volatility, particularly in parts of fixed income where liquidity dried up. 
· In an exclusive interview, Salim Ramji, the global head of iShares and index investments for BlackRock, shared the growth opportunity this period showcased — and more he sees...