Lai Cao Mai Phuong

This article uses an event study to investigate the response of a bank’s stock price to information related to these banks’ top managers. In the first event, the Vice Chairman of the founding board of Asia Commercial Bank (ACB) was arrested and the Chief Executive Officer (CEO) of this bank was summoned by the police for questioning. The second event related to the immediate resignation of the Chairman of the Board of Directors of Sacombank (STB) after he received a summons from the investigating police agency. Both of these events happened in Vietnam. The research results showed that unanticipated events (the first event) caused the share prices of both banks to react more strongly, and the impact time was longer than the second event. The first event resulted in the cumulative abnormal returns of ACB and STB being –23.6% and –9.1%. The second event has been found to be directly related to STB, but does not significantly affect this stock, but has a significant effect on the abnormal return of ACB (AR (1) = –4.6%). Asymmetric information, inattention and investor fear of event-related losses may explain this phenomenon.

This paper investigated how food and beverage (F&B) stocks react to COVID-19. The event study method was applied to four events including the first and second events, were the first COVID-19 positive patients detected in the largest and second-largest economic center of Vietnam. The third and fourth events are related to strong measures to prevent the spread of COVID-19: the nationwide lockdown at the beginning of the second quarter of 2020, and the lockdown of Danang at the beginning of the third quarter of 2020. The results show that the reaction of F&B stock prices to events supports the semi-strong form of efficient market theory. The strong and lasting negative reaction of F&B stocks to the first event can be explained by surprise (first case in Vietnam) and Hochiminh city’s economic engine driving role in the development of Vietnam’s economy. The study finds that heuristic decision-making from nationwide lockdowns (suppression of supply chains during lockdowns) can explain the sub-sector of farming-fishing-ranching products reacted more strongly to the lockdown event in Danang. Based on the research results, this paper provides some policy implications for managers and notes for securities investors.

The purpose of this study is to examine whether investor sentiment as measured by technical analysis indicators has an impact on stock returns. The research period is from 2015 to mid-2020. 1-year government bond yields, financial data, transaction data of 57 companies in the VN100 basket, and VNIndex are analyzed. The investor sentiment variable is measured by each technical analysis indicator (Relative Strength Index – RSI, Psychological Line Index – PLI), and the general sentiment variable is established based on extracting the principal component from individual indicators. The paper uses two regression methods – Fama-MacBeth and Generalized Least Square (GLS) – for five different research models. The results show that sentiment plays an important role in stock returns in the Vietnamese stock market. Even controlling the factors such as cash flow per share, firm size, market risk premium, and stock price volatility in the studied models, the impact of sentiment is significant in both the model using individual technical indicators and the model using the general sentiment variable. Furthermore, investor sentiment has a stronger power to explain excess stock returns than their trading behavior. The implication from the results shows that the Vietnamese stock market is inefficient, in which psychology is a very important issue and participants need to pay due attention to this factor.

Acknowledgment
This study was funded by the Industrial University of Ho Chi Minh City (IUH), Vietnam (grant number: 21/1TCNH03).

This paper investigates whether there exists a Bowman paradox on the relationship between risk-return for Vietnamese firms. Data in the annual audited financial statements from 2017 to 2020 of 727 enterprises listed on the Vietnamese stock market are used in this study. The data set is divided into two different groups based on the reference point, which is the average return of the whole market and by industry. Correlation analysis and ordinary least square regression according to cross sectional data were performed in this study. After controlling for size, debt-to-total assets, and debt-to-equity ratios, the research results show that the risk-return relationship of the two groups of firms is mixed and can be explained by prospect theory. There exists Bowman's paradox for a group of firms whose return is below the reference point, these firms tend to seek risk versus return, so their risk-return relationship is negative. In contrast, this relationship is positive for the group of firms whose returns are above the reference point, or which tend to avoid risk. The slope coefficient of the group of enterprises below the reference point compared to the rest of enterprises is 2.5:1, which correctly reflects the ratio of the risk-seeking area to the risk-avoiding area in prospect theory.

Using macroeconomic factors as control variables, this paper examines the impact of corruption on the development of the stock market in East Asia and the Pacific (EAP) from 2008 to 2018. The research model uses GMM techniques to estimate panel data on two sub-sets of data, including five developed markets and seven emerging markets, and a dataset of both market groups. The market capitalization and the stock transaction value relative to GDP represent the development of the stock market, and the corruption control index represents the corruption factor. The empirical results found that corruption has a positive impact on the EAP stock market capitalization with the entire sample data set, which positively affects both size of the market capitalization value and value of stock transactions in underdeveloped markets. However, it is not statistically significant in explaining the development of developed stock markets. Besides, macroeconomic factors such as inflation, interest rates, savings, and credit affect some stock markets at EAP. Compared to previous studies, the article’s results found that corruption affects stock market capitalization and has a positive impact on stock liquidity in underdeveloped stock markets. Corruption affects more underdeveloped stock markets than developed stock markets. This may be due to the implicit relationship of economic benefits between large enterprises and officials in underdeveloped markets.

The banking industry is one of the major industries in the Vietnamese stock market, so understanding how the industry index reacts to unusual events such as COVID-19’s impact is very important for the development of the Vietnamese stock market. This study examines the response of the banking sector index to three lockdown/blockage announcements to prevent the COVID-19 epidemic in Vietnam in 2020. Three times of lockdown/blockage: On February 13, 2020, blockade of Son Loi commune, Vinh Phuc province; on March 30, 2020, Vietnam announced the nationwide epidemic of COVID-19 and then nationwide lockdown, and on July 28, 2020, blockade in Da Nang. In the first case, the abnormal returns changed the sign around the notification date indicating that the stock price deviated from its fair value, but accumulating abnormal returns CAR (0;3] and CAR (0; 2] are both positive and statistically significant, which means that investors are more secure when the epidemic area is tightly controlled. The nationwide lockdown was the event that had the strongest impact on the stock price when both AR and CAR were negative and statistically significant before and after the date of the event’s announcement. Nationwide lockdown was the event that had the strongest impact on stock prices as both AR and CAR were negative in the days before and days after the event. This result supports the theory of imperfect substitution. Only AR [2] was positive and statistically significant, showing that the blockade event in Da Nang had a slight impact on the banking sector’s stock price.