XLG is the ETF for investors who don't want to hold any companies they haven't heard of. It tilts much larger than its broad-based benchmark and is slightly less volatile due to its exposure to the S&P 500Top 50 Index. Constituents are derived from 50 of the largest companies in the S&P 500Index based on float-adjusted market capitalization thus reflecting U.S. mega-cap performance. Following a full replication methodology, the fund and its Underlying Index are rebalanced annually and a buffer rule is applied in the constituent selection process at each rebalancing in order to reduce turnover.
