All three are poised to keep growing, and they recently had solid dividend yields, too.For many individual investors, the best way to build wealth over the long run is with one or more simple, low-fee index funds, which can be all we need to build secure financial futures.Index funds require little brain power from us and little attention. Keep adding money to the funds over many years, and they should grow well for you, delivering roughly the same returns as the indexes they track.An S&P 500 index fund, fo ...