Comment: Forthcoming in Finance Research Letters. arXiv admin note: substantial text overlap with arXiv:2201.05709Using the peer-exposure ratio, we explore the factor exposure heterogeneity in green and brown stocks. By looking at peer groups of S&P 500 index firms over 2014-2020 based on their greenhouse gas emission levels, we find that, on average, green stocks exhibit less factor exposure heterogeneity than brown stocks for most of the traditional equity factors but the value factor. Hence, investment managers shifting their investments from brown stocks to green stocks have less room to differentiate themselves regarding their factor exposures. Finally, we find that factor exposure heterogeneity has increased for green stocks compared to earlier periods.