Effects of investor sentiment and country governance on unexpected conditional volatility during the COVID-19 pandemic: Evidence from global stock markets

This paper first investigates the relationship between investor sentiment, captured by internet search behaviour, and the unexpected component of stock market volatility during the COVID-19 pandemic. According to data on 12 major stock markets, our research indicates a positive correlation between the Google search volume index on COVID-19 and the unexpected volatility of stock markets. The result suggests that greater COVID-19-related investor sentiment during this pandemic is associated with higher stock market uncertainty.Our study further examines whether country-level governance plays a role in protecting stock markets during this pandemic and reveals that the unexpected conditional volatility is lower when a country's governance is more effective. The impact of investor sentiment and country governance on unexpected volatility after the initial shock of COVID-19 is also investigated. The findings demonstrate the importance of establishing good country-level governance that can effectively reduce stock market uncertainty in the context of this pandemic, and support continual policy development related to investor protection.     

Together we invest? Individual and institutional investors' trading behaviour in Poland

This paper contributes to the debate about individual and institutional investors' trading behaviour with new evidence from the Polish stock market. While most existing studies focus on institutional investors' trading in developed markets, we test for the presence of herding during market up- and downswings on an emerging market. Our unique approach is to combine an established method relying on daily prices with institutional features of the Warsaw Stock Exchange. It enables us to separate individuals from institutions by examining two trading mechanisms with different investor structures. The empirical results suggest that individuals engage in herding during market downswings, while there is less evidence of imitating trading behaviour in bullish markets. Regardless of the state of the market, institutions' trading behaviour does not appear to exhibit herd behaviour. Further evidence suggests that herding by individuals becomes less pronounced over time.     

Investor attention and global market returns during the COVID-19 crisis

The financial market response to the COVID-19 pandemic provides the first example of a market crash instigated by a health crisis. As such, the crisis provides a unique setting in which to examine the market response to changes in investor attention. We utilise Google search volume (GSV) as a proxy for investor attention. GSV for the “coronavirus” keyword increases markedly from late-February and peaks in mid-March before declining substantially. Our results are broadly consistent with Da, Engelberg, and Gao (2015), indicating that GSV is primarily a proxy for the attention of retail investors and confirming that investor attention negatively influences global stock returns during this crisis period. A rise in the number of internet searches during the COVID-19 crisis induces a faster rate of information flow into financial markets and so is also associated with higher volatility. The identified relationships are economically and statistically significant even after controlling for the number of COVID-19 cases and macroeconomic effects. Increases in GSV have less impact on government bond yields where the limited role of GSV is likely due to lower participation of retail investors. The results suggest that, rather than searching for information on potential stocks to buy (Barber & Odean, 2008), retail investors are searching for information to resolve uncertainty about household FEARS (Da et al., 2015) during the COVID-19 crisis.     

How does the COVID-19 pandemic shape the relationship between Twitter sentiment and stock liquidity of US firms?

Using a new investor sentiment metric derived from Twitter, this paper examines how the pandemic's death rate influences the impact of investor sentiment on stock liquidity. Recent literature remains inconclusive regarding the effect of COVID-19 information and investor sentiment on financial markets. Using panel smooth transition regression (PSTR) for daily data on 338 listed firms in the S&P500 from January 2, 2020, to May 26, 2021, the findings reveal that the impact of Twitter sentiment on stock liquidity is nonlinear and changes over time and across firms in the function of the pandemic's death rate in the US. The results exhibit a threshold level of 4.32%, above which investor sentiment boosts stock liquidity. The speed of the transition from low to high pandemic death rate regime occurred abruptly rather than smoothly. This translates to severe changes in investor perception and demonstrates that investors are rapidly updating their beliefs during the COVID-19 outbreak.     

The influence of the COVID-19 pandemic on asset-price discovery: Testing the case of Chinese informational asymmetry

The circumstances surrounding the outbreak of the COVID-19 pandemic have generated substantial international political strain as governments attempt to mitigate the widespread associated social and economic repercussions. One theory has focused on the potential for Chinese informational asymmetry. Using Chinese financial market data, we attempt to establish the scale and direction of information flows during multiple distinct phases of the development of the pandemic. Two specific results are identified. Firstly, the majority of domestically-traded Chinese stocks present evidence of significant information flows at a far earlier stage than internationally-traded comparatives, suggesting that domestic investors recognised the dangers associated with COVID-19 far in advance of the rest of the world. One potential explanation surrounds the view that the severity of domestically-reported Chinese news was not appropriately recognised by international investors. Secondly, while evidence of safe-haven and flight-to-safety behaviour is evident throughout traditional energy and precious metal markets, cryptocurrencies became informationally-synchronised with Chinese equity markets, indicating their use as an investor safe-haven. This is a particularly concerning outcome for international policy-maker and regulatory authorities due to the fragility of these developing markets.     

COVID-19, government interventions and emerging capital markets performance

In this study, we explore the impact of government intervention to contain the spread of COVID-19 in emerging countries on the performance of their leading stock indices. We retrieved data on the performance of 25 international capital market indices included in the MSCI Emerging Markets Index and data about the closures, economic, and health measures imposed in each country examined. Overall, our findings show that government restrictions are associated with negative market returns, possibly due to the anticipated adverse effect to the economy. The adverse effect is more evident when closures are imposed. The market response to economic stimulus is mild but varies depending on the type of intervention imposed, much as with the health measures. Public campaigns may raise public awareness about COVID-19, but they can also increase the public’s fear of the pandemic, reflected in the negative response in capital markets. The results are essential for understanding the trends and fluctuations in emerging markets during this current crisis and for preparing for crises in the future.     

Institutional herding in international markets

This paper studies herding behavior of institutional investors in international markets. First, we document the existence of wide-spread herding in 41 countries (referred to as “target countries” hereafter) in the sample. We then examine the relation between contemporaneous institutional demand and future returns and find that institutional herding stabilizes prices. Next, we examine the relation between institutional investors’ herding behavior and the level of information asymmetry in the target countries. We measure the degree of information asymmetry in each target country along five dimensions: (1) stock market development, (2) ease of access to information, (3) corporate transparency, (4) investor rights, and (5) macroeconomic factors that relate to the information environment. We find evidence that institutional investors herd more in markets characterized by low levels of information asymmetry (high level of information transparency). This result suggests that institutional investors’ herding behavior is likely driven by correlated signals from fundamental information. Lastly, we show that price adjustment is faster in informationally transparent markets.     

Stock markets’ reaction to COVID-19: Cases or fatalities?

In this paper, we examine the stock markets’ response to the COVID-19 pandemic. Using daily COVID-19 confirmed cases and deaths and stock market returns data from 64 countries over the period January 22, 2020 to April 17, 2020, we find that stock markets responded negatively to the growth in COVID-19 confirmed cases. That is, stock market returns declined as the number of confirmed cases increased. We further find that stock markets reacted more proactively to the growth in number of confirmed cases as compared to the growth in number of deaths. Our analysis also suggests negative market reaction was strong during early days of confirmed cases and then between 40 and 60 days after the initial confirmed cases. Overall, our results suggest that stock markets quickly respond to COVID-19 pandemic and this response varies over time depending on the stage of outbreak.     

Corporate governance and stock performance: The case of COVID-19 crisis

This paper analyzes the impact of COVID-19 on firm-level stock behaviors (including stock price volatility, trading volume and stock returns). Using US data, this paper examines whether confirmed cases (and deaths) of COVID-19 or COVID-19-associated online searches affect stock behaviors. The results show that our five COVID-19 proxies are all positively associated with stock price volatility and trading volume and negatively associated with stock returns. This paper further investigates the mitigating effect of corporate governance (viz., board and ownership structures) in this COVID-19 crisis. Overall, the results suggest that good corporate governance can mitigate the impact of COVID-19 on stock price volatility and trading volume but may not help to enhance stock returns. This paper also considers key policies used to tackle the COVID-19 pandemic and finds that government intervention plays an important role in stabilizing stock markets in this COVID-19 crisis.     

Analysis of risk correlations among stock markets during the COVID-19 pandemic

The outbreak of the COVID-19 pandemic significantly negatively impacted the global economy and stock markets. This paper investigates the stock-market tail risks caused by the COVID-19 pandemic and how the pandemic affects the risk correlations among the stock markets worldwide. The conditional autoregressive value at risk (CAViaR) model is used to measure the tail risks of 28 selected stock markets. Furthermore, risk correlation networks are constructed to describe the risk correlations among stock markets during different periods. Through dynamic analysis of the risk correlations, the influence of the COVID-19 pandemic on stock markets worldwide is examined quantitatively. The results show the following: (i) The COVID-19 pandemic has caused significant tail risks in stock markets in most countries, while the stock markets of a few countries have been unaffected by the pandemic. (ii) The topology of risk correlation networks has become denser during the COVID-19 pandemic. The impact of the COVID-19 pandemic makes it easier for risk to transfer among stock markets. (iii) The increase in the closeness of the risk relationship between countries with lower economic correlation has become much higher than that between counties with higher economic correlation during the COVID-19 pandemic. For researchers and policy-makers, these findings reveal practical implications of the risk correlations among stock markets.     

Herd behaviour & investor sentiment: Evidence from UK mutual funds

The aims of this paper are to detect evidence of institutional investor herding behaviour and examine the role that investor sentiment plays in institutional investor herding behaviour. The herding behaviour is investigated by examining the dispersion of time varying beta of UK open-end and closed-end funds. The study finds evidence of fund managers' herding behaviour, which suggests they are likely to herd on market portfolio, size, and value factors. UK market-wide investor sentiment index is used for investigating the effects of investor sentiment on institutional herding behaviour. We find a unidirectional investor sentiment effect on the herding of UK mutual fund managers. We also reveal that the sentiment factors affecting UK open-end and closed-end fund managers herding behaviour are different due to the differences in fund structure.     

中国股市羊群效应的区制转移时变性研究

传统研究采用静态CCK模型检验股票市场的羊群效应,但无法描述羊群行为的动态变化以及市场可能受到的外部影响。本文基于中国股市日频交易数据,在静态CCK模型中引入参数的区制转移性质识别股市在不同状态间的转换,并分析中国股市羊群效应和交叉羊群效应的时变特征。研究表明,中国股市运行周期可被划分为两个区制,分别呈现低波动和高波动的行情特征;羊群效应的程度随区制转移而变化,具有区制依存性。其中,沪深股市在高(低)波动区制中,羊群效应更强(弱),相应区制持续时间较短(长);中国台湾股市仅在高波动区制中出现羊群效应,相应区制持续时间较短;中国香港股市无论在低波动区制或是高波动区制中,均不存在羊群效应。此外,沪深A股在低波动区制中对美国股市和中国香港股市存在交叉羊群效应。     

Pandemic-driven financial contagion and investor behavior: Evidence from the COVID-19

This paper studies the pandemic-driven financial contagion during the COVID-19 period and the impact of investor behavior on it by constructing three types of direct behavior measurements based on Google search volumes. More specifically, using a sample of 26 major stock markets around the world during the COVID-19 pandemic, we construct a non-linear financial contagion network via a dynamic mixture copula-EVT (extreme value theory) model to quantitatively detect and measure the complex nature of pandemic-driven financial contagion. Furthermore, through constructing direct investor behavior measurements including investor attention, sentiment, and fear, we find investor behavior plays an important role in explaining pandemic-driven financial contagion. We also find that the impacts of investor behavior on the pandemic-driven financial contagion are heterogeneous under several different settings, including market conditions, market development levels, regional subsets, and contagion directions.     

Retail investor attention and herding behavior

In this paper, we argue that when individual investors can obtain information from public resources such as Google search, the degree of investor attention to a particular underlying company is positively linked with herding behavior for retail investors. Empirical results confirm that Google Search Volume Index can be a proxy for the information demand of uninformed individual investors. Empirical evidence also shows that reaching the price limit generates an attention-grabbing effect. Further, in general, small cap firms generate more intensive individual investor herding. In addition, we explore the asymmetric impact of abnormal search volume index on individual investor herding behavior for bull and bear markets, and confirm that the individual investor buy herding phenomenon is stronger in bull markets, especially for small capitalization firms. In bear markets, with greater price deterioration for large cap firms, we detect herding behavior on the sell side.     

Constructing a positive sentiment index for COVID-19: Evidence from G20 stock markets

The present study investigates the degree of market responses through the scope of investors' sentiment during the COVID-19 pandemic across G20 markets by constructing a novel positive search volume index for COVID-19 (COVID19⁺). Our key findings, obtained using a Panel-GARCH model, indicate that an increased COVID19⁺ index suggests that investors decrease their COVID-19 related crisis sentiment by escalating their Google searches for positively associated COVID-19 related keywords. Specifically, we explore the predictive power of the newly constructed index on stock returns and volatility. According to our findings, investor sentiment positively (negatively) predicts the stock return (volatility) during the COVID-19. This is the first study assessing global sentiment by proposing a novel proxy and its impacts on the G20 equity market.     

What can we learn about the market reaction to macroeconomic surprise? Evidence from the COVID-19 crisis

We investigate the impact of macroeconomic surprise and uncertainty on G7 financial markets around COVID-19 pandemic using two real-time, real-activity indexes recently constructed by Scotti (2016). We applies the wavelet analysis to detect the response of the stock markets to the macroeconomic surprise and an uncertainty indexes and then we use NARDL model to examine the asymmetric effect of the news surprise and uncertainty on the equity markets. We conduct our empirical analysis with the daily data from January, 2014 to September, 2020. Our findings indicate that G7 stock markets are sensitive to the macroeconomic surprise and uncertainty and the effect is more pronounced at the long term than the short term. Moreover, we show that the COVID-19 crisis supports the relationship between the macroeconomic indexes and the stock prices. The results are useful for investment decision-making for the investors on the G7 stock indices at different investment horizons.     

How Does Investor Sentiment Affect Stock Market Crises? Evidence from Panel Data

We test the impact of investor sentiment on a panel of international stock markets. Specifically, we examine the influence of investor sentiment on the probability of stock market crises. We find that investor sentiment increases the probability of occurrence of stock market crises within a one‐year horizon. The impact of investor sentiment on stock markets is more pronounced in countries that are culturally more prone to herd‐like behavior, overreaction and low institutional involvement.     

Impact of COVID-19 on stock market efficiency: Evidence from developed countries

This study investigates the impact of the novel coronavirus (COVID-19) pandemic on stock market efficiency for six hard-hit developed countries, namely, the United States (US), Spain, the United Kingdom (UK), Italy, France, and Germany. Applying the wild bootstrap automatic variance ratio test on daily stock market data from July 29, 2019 to January 25, 2021, it is found that all stock markets used in this study deviate from market efficiency during some periods of the pandemic. Deviations from market efficiency are seen more in the stock markets of the US and UK during the COVID-19 outbreak than in other stock markets. These results are strengthened when a different econometric method, the automatic portmanteau test, is used. The findings of this study indicate an increasing chance for stock price predictions and abnormal returns during the COVID-19 pandemic.     

Bond market investor herding: Evidence from the European financial crisis

During the recent financial crisis, numerous EU officials, market participants and the media suggested that irrational herding was a key factor for the financial turmoil and the soaring yield spreads. In this paper we test for evidence of herd behavior in European government bond prices and, overall, we find no evidence of investor herding either before or after the EU crisis. We do find, however, in an original contribution to the bond market literature, strong evidence that during the EU crisis period, macroeconomic information announcements induced bond market investor herding; a finding that confirms the notion of ‘spurious’ herding proposed by Bikhchandani and Sharma (2001) for bond markets. Further tests reinforce this finding and also indicate the existence of herding spill-over effects.     

重大突发公共卫生事件下的金融市场反应

本文旨在评估金融市场对重大突发公共卫生事件的反应,尤其是上市公司所在地的公共治理能力是否会影响上市公司股票收益率。其中,城市公共治理能力以基于实时数据计算的防疫能力和复工复产能力指标来刻画。主要发现如下:第一,防疫能力会影响投资者情绪,但不会直接影响股票收益率;第二,所在地复工复产能力对股票收益率存在正向影响;第三,机制分析表明,经营基本面更容易受疫情影响的企业,如小企业、成长型企业、所在地数字金融基础设施较差的企业,其股票收益率对当地复工复产能力的反应更敏感。本文结论表明,在全国一盘棋的抗疫努力下,投资者对于战胜疫情有信心,短期内复工复产能力对金融市场更重要。从应对措施来看,短期内可对比较脆弱的企业实施精准果断的帮扶,长期内可考虑加强地区防疫能力建设和数字基础设施建设。