Dimensional Fund Advisors (DFA), a fund giant known mainly for its smart beta strategies, converted four of its tax-managed mutual funds with $28.8 billion of assets into ETFs last week and became one of the top 15 ETF issuers.More than $1 trillion worth of mutual fund assets could be converted into ETFs in the coming decade, per Bloomberg. Citigroup, which acted as the transfer agent for the conversion, believes that $21 trillion mutual fund industry could consist mostly of ETFs within the next decade.Over the past decade, we have seen mutual funds losing assets to ETFs as investors prefer ETFs which are generally more tax efficient, cheaper, and easier to trade. US listed ETFs have already gathered more than $450 billion in assets so far this year.For long-term focused investors, ETFs like the Vanguard S&P 500 ETF (VOO), Vanguard Total Stock Market ETF (VTI), and Invesco NASDAQ 100 ETF (QQQM) are very appealing. Apple (AAPL), Microsoft (MSFT), Amazon (AMZN) and Tesla (TSLA) are the top holdings in these funds. To learn more about these ETFs, please watch the short video above.Want key ETF info delivered straight to your inbox?Zacks’ free Fund Newsletter will brief you on top news and analysis, as well as top-performing ETFs, each week. Get it free >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report Alphabet Inc. (GOOG): Free Stock Analysis Report Apple Inc. (AAPL): Free Stock Analysis Report Microsoft Corporation (MSFT): Free Stock Analysis Report Tesla, Inc. (TSLA): Free Stock Analysis Report Invesco QQQ (QQQ): ETF Research Reports Vanguard Total Stock Market ETF (VTI): ETF Research Reports Vanguard S&P 500 ETF (VOO): ETF Research Reports Invesco NASDAQ 100 ETF (QQQM): ETF Research Reports To read this article on Zacks.com click here. Zacks Investment Research Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report