A reader was kind enough to pass along this Mark Hulbert story (free registration required) from The New York Times that indicates that all-ETF portfolios tracked by his service have "turned in disappointing results."Hulbert notes that his research sample size might be too small, but the results are what they are. The reader wanted my opinion on the outcome. I would tie this in to what I have been writing all along about all-ETF portfolios and investment products in general: They all have flaws that need to be understood and possibly mitigated through prudent portfolio management. I first touched on this idea about a year and a half ago on my blog, but it's worth repeating: An all-ETF portfolio is not a great way to go. The biggest flaw with ETFs is that they often yield less than common stocks. I said back then that the consequence is that an all-ETF portfolio has a much heavier reliance on price appreciation, and in a flat market like we have had recently, all-ETF portfolios will lag a stock portfolio that includes stocks with large dividends. Another issue that could account for Hulbert's results might be that most all-ETF portfolios use what I believe are the wrong ETFs. Most of the products I have seen rely too much on cap size and style ETFs and very rarely do they use sector and single-country ETFs. I have disclosed before that I use a lot of ETFs to assemble some client portfolios, but none of them are 100% ETFs, even if they do have a lot, and only in extenuating circumstances do I use any style or cap-size ETFs. For these accounts I use sector ETFs and weight them the way I weight sectors in regular accounts.