Sector Performance and Concentration

Roman Kouzmenko and Juan Sampieri

Sector composition and concentration in global equity markets changed dramatically over the past 20 years. For example, the combined weight of information technology and communication services exceeded 40% of the MSCI USA Index as of the end of September 2020 — above those sectors’ previous dot-com-bubble top. In September 2020, Amazon.com alone had a weight of 37% of consumer discretionary in the U.S. index, while Alibaba represented over 43% of the MSCI Emerging Markets Consumer Discretionary Index.