Total US-listed ETF assets reached $3.81 trillion at the end of Q1 2019, a 10.3% year-over-year increase. Estimated net asset flows in Q1 2019 totaled $54 billion, a 31% drop from the prior four quarter average.

Taxable Bond ETFs received the strongest estimated net inflows in Q1 2019, totaling $34 billion, bringing the category's year-over-year increase in total assets to over 20%. Municipal Bond ETFs received $1.1 billion in estimated net inflows in Q1 2019, increasing year-over-year assets by 26%.

US Equity ETFs received the second highest estimated net inflows with $17 billion, bringing the category's year-over-year increase in total assets to 16%. The narrower Sector Equity ETFs category saw estimated net outflows of $5 billion, and was the only category with estimated net outflows in both Q4 2018 and Q1 2019.

International Equity ETFs received $8 billion in estimated net inflows, although year-over-year assets in the category declined 3%, in light of negative performance.

Commodities and Allocation ETFs had estimated net outflows of $0.7 billion and $1.0 billion, respectively, in Q1 2019.