VOX holds companies that provide communication services, as defined by GICS. The fund includes traditional telecoms as well as media and internet services companies that were previously classified in the consumer discretionary and tech sectors under the old GICS standard prior to 2018. Before May 3, 2018, the fund tracked the MSCI US Investable Market Telecommunication Services 25/50 Index. The fund then tracked a transition index until December 3, 2018, when final GICS changes were officially implemented. While the fund is concentrated in a few heavyweights like Alphabet (Google), Facebook, and Verizon, it still captures stocks across all capitalization. Like all Vanguard ETFs, VOX discloses its holdings monthly instead of daily. The index is reviewed and rebalanced quarterly.