Lee, NamhoonChoi, WonseokYuntaek, Pae2023-03-232023-03-232021This is a post-print version of an article that is available at https://doi.org/10.1016/j.econlet.2021.109931. Recommended citation: Lee, N., Choi, W., & Pae, Y. (2021). Market efficiency in foreign exchange market. Economics Letters, 205, 109931. This item has been deposited in accordance with publisher copyright and licensing terms and with the author’s permission.https://hdl.handle.net/11274/14717https://doi.org/10.1016/j.econlet.2021.109931Article originally published in Economics Letters, 205, 109931. English. Published online 2021. https://doi.org/10.1016/j.econlet.2021.109931Post-print under embargo until August 2023The study examines foreign exchange market overreaction for various combinations of formation and testing periods over 30 years. First, we find that reversal is significant for longer test periods and longer formation periods. Second, we find no evidence of persistent momentum or reversal during the entire sample period. Thus, the results of overreaction studies should be sensitive to the sample period. Third, we observe losers outperform most of the formation and test periods combinations except for the short-term when spot rates are used to construct portfolios. We observe the evidence of overreaction becomes stronger with the longer formation and test period.en-USOverreactionReversalMomentumForeign exchange rateEfficient market hypothesisPost-Print