This study examines the effect of investor sentiment on the Vietnamese stock market. Using the results of international football matches as exogenous shocks on investor sentiment, and information from two major stock exchanges, we document a link between investor sentiment and stock market returns. In particular, we find a decline in market returns on the subsequent trading days after game losses. Moreover, the effect of investor sentiment on stock market returns is more pronounced between 2015 and 2020 during which football fans exhibited a stronger affection and attention to their teams. The results further depict that the impact of investor sentiment on stock market returns is only significant for small-cap stocks, and when more important tournaments are played.

这项研究考察了投资者情绪对越南股市的影响。使用国际足球比赛的结果作为对投资者情绪的外来冲击，以及来自两个主要证券交易所的信息，我们记录了投资者情绪与股市收益之间的联系。尤其是，我们发现游戏损失后的随后交易日市场回报有所下降。此外，在2015年至2020年期间，投资者情绪对股票市场回报的影响更加明显，在此期间，足球迷们表现出了对球队的浓厚兴趣和关注。结果进一步表明，投资者情绪对股市收益的影响仅对小型股以及在进行更重要的比赛时才有意义。