First-quarter inflows into exchange-traded funds totaled $53.1 billion, with $16.9 billion coming in March, according to a Morningstar report issued Thursday.
The three months ended March 31 marked the fourth out of the past five quarters in which inflows surpassed $50 billion; inflows in the second quarter 2012 totaled $25.4 billion, Michael Rawson, fund analyst at Morningstar, said in an e-mail.
U.S. equity ETFs gained the most of any asset class in March, with $11.2 billion, followed by fixed-income ETFs at $4.8 billion.
Vanguard's market share was 19% as of March 31, up from 16.9% a year ago. Market share for iShares declined from a year earlier, to 40.8% from 41.3%; State Street's share was 23.5%, down from 24.7%.
Among other ETF providers, WisdomTree, Pacific Investment Management and Schwab have gained market share in the last year, while PowerShares, Van Eck, ProShares, and Deutsche Bank have lost ground.
Commodities and international stocks were the only asset classes that saw outflows in March. Investors pulled $2.4 billion from commodities ETFs last month while $4.1 billion in outflows came from diversified emerging-markets ETFs in March, their first monthly outflow since May 2012.