Preliminary figures from ETFGI shows $522bn (£366bn) was invested in the funds at the end of March. The market also saw its 18th consecutive month of net inflows, totalling $5.11bn.
The data also showed that, globally, assets invested in ETFs exceeded $3 trillion for the second time.
Deborah Fuhr, managing partner at ETFG, told City A.M. the growth of investment in ETFs - collective investment vehicles which in most cases passively replicate the performance of a particular index - has been fuelled in part by underperforming active fund managers.
She said: “Many active managers are actually following indices quite closely - they call them closet indexers. Why would I pay active fees, which are much higher than index or ETF fees, for someone who's basically tracking an index but not saying that's what they're doing?”
The global sector has 6,240 funds or products, with 12,042 listings, and assets of $3.07 trillion from 277 providers listed on 64 exchanges in 51 countries, according to preliminary data from ETFGI's March 2016 report.
Fuhr told City A.M. ETFGI's outlook for the sector is “still positive”. She added: “We've seen studies coming out from S&P showing that asset managers are still struggling to deliver performance above benchmarks, that investors are increasingly using ETFs for asset allocations, and they're also being used instead of futures and other products.”