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                             iShares Core S&P U.S. Total Market Index ETF (XUU $69.88) iShares Core S&P U.S. Total Market Index ETF (XUU $69.88)
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                             Vanguard U.S. Total Market Index ETF (VUN $126.99) Vanguard U.S. Total Market Index ETF (VUN $126.99)
            Q: Please correct me where I am wrong, but these two ETF's track the same index (un-hedged US total market), but in spite of XUU having a lower MER, VUN seems to be the more popular choice, as well as seems to have a higher amount of daily trading volume.  Any idea why?
        
     
                             
                             
                    