"Almost 80% of the ETF assets are invested in equity ETFs, which have the highest return: 8% over the last 5 years vs. 4% for the average ETF. So the majority of the assets are producing high returns. The top 37 ETFs that have combined assets of $1.5 trillion (or half of the entire US ETF market) have an average expense ratio of 0.15% vs. 0.59% for all ETFs. " From: Why US Investors Are Smart
