The InfraCap MLP ETF (AMZA) was launched on 10/14/2014, and is a passively managed exchange traded fund designed to offer broad exposure to the Energy - MLP segment of the equity market.Retail and institutional investors increasingly turn to passively managed ETFs because they offer low costs, transparency, flexibility, and tax efficiency; these kind of funds are also excellent vehicles for long term investors.Sector ETFs are also funds of convenience, offering many ways to gain low risk and diversified exposure to a broad group of companies in particular sectors. Energy - MLP is one of the 16 broad Zacks sectors within the Zacks Industry classification. It is currently ranked 9, placing it in bottom 44%.Index DetailsThe fund is sponsored by Infracap Mlp Etf. It has amassed assets over $650.08 M, making it one of the larger ETFs attempting to match the performance of the Energy - MLP segment of the equity market.This ETF is active and does not track a benchmark.CostsInvestors should also pay attention to an ETF's expense ratio. Lower cost products will produce better results than those with a higher cost, assuming all other metrics remain the same.Annual operating expenses for this ETF are 1.36%, making it the most expensive product in the space.It has a 12-month trailing dividend yield of 21.82%.Sector Exposure and Top HoldingsETFs offer a diversified exposure and thus minimize single stock risk but it is still important to delve into a fund's holdings before investing. Most ETFs are very transparent products and many disclose their holdings on a daily basis.Looking at individual holdings, Eqt Midstream Partners Lp (EQM) accounts for about 12.40% of total assets, followed by Andeavor Logistics Lp (ANDX) and Energy Transfer Partners Lp (ETP).The top 10 holdings account for about 79.88% of total assets under management.Performance and RiskThe ETF return is roughly 4.18% and it's up approximately 2.82% so far this year and in the past one year (as of 09/07/2018), respectively. AMZA has traded between $6.71 and $9.43 during this last 52-week period.The ETF has a beta of 1.77 and standard deviation of 37.94% for the trailing three-year period, making it a high risk choice in the space. With about 221 holdings, it effectively diversifies company-specific risk.Bottom LineTo learn more about this product and other ETFs, screen for products that match your investment objectives and read articles on latest developments in the ETF investing universe, please visit Zacks ETF Center.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 INFRACAP MLP (AMZA): ETF Research Reports Energy Transfer Partners, L.P. (ETP): Free Stock Analysis Report EQT Midstream Partners, LP (EQM): Free Stock Analysis Report Tesoro Logistics LP (ANDX): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research