Abstract
With a large proportion of retail investors, the Vietnamese stock market is still heavily influenced by sentimental factors rather than fundamental factors. Therefore, the issue of stabilizing market sentiment is increasingly essential to protect investors and ensure the development of market securities. The PCA is employed to construct a sentiment index for the Vietnamese stock market. The result shows that the investor sentiment in the Vietnamese stock market has fluctuated over time. Moreover, the index reflects the impact of several political and economic events on investor sentiment in the stock market. This study summarizes policies that the government has implemented to solve objective and subjective reasons for fluctuations in investor sentiment. Moreover, this study also recommends several improvements in policies to stabilize investor sentiment and protect vulnerable investors in the Vietnamese stock market.