XLE offers liquid exposure to a market-like basket of US energy firms. Market-like in the context of the energy sector means concentrated exposure to the giants in the industry, including companies in the oil, gas and consumable fuels, and energy equipment and services industries as identified by GICS. XLE pulls its stocks from the S&P 500 rather than the total market, so its portfolio mainly favors large-caps. Holdings are weighted by market cap, subject to a capping methodology that ensures no single security exceeds 25% at each quarterly rebalance.