Despite the name recognition that comes from tracking the Dow and its own popularity, DIA is not the ideal ETF for investors who want broad-based exposure to US large-caps. The fund`s tiny portfolio, arbitrary selection, and antiquated weighting produce significant sector biases relative to the market, and cover only a fraction of the large-cap space, typically represented by hundreds of names. Stocks are price-weighted, not cap-weighted, which can produce major sector realignments when multiple holdings change, as occurred in September 2013. Still, DIA tends to move with the broader market day-to-day, and some may prefer its typically (slightly) lower beta. DIA is extremely liquid, with huge assets and a long track record. The fund`s UIT structure is shared by a few other long-lived ETFs (like SPY), with the most notable effects being a slight cash drag since stock dividends received in between the ETF`s distributions can`t be reinvested as is typically the case. UITs must also hold every stock in the index at all times, which can tie the PM`s hands. Still, for exposure to the Dowa concentrated, universally-cited basket of household namesDIA is a great choice.