This ETF offers exposure to the U.S. energy industry, including many of the world's largest oil producers. While XLE probably doesn't make sense for those constructing a long-term buy-and-hold portfolio, it can be potentially useful as a tactical overlay for those looking to shift exposure towards a sector that thrives when oil prices show strength. Compared to other energy options, XLE is impressive in terms of both cost efficiency and liquidity; investors can generally expect to execute at penny wide spreads. But like many funds offering exposure to the energy sector, XLE maintains some concentration issues, as a few stocks account for big chunks of the total portfolio. Those seeking to avoid this issue may like the equal weighted RYE; the alpha-seeking FXN may also be an intriguing option for energy exposure.