The impacts of investors' sentiments on stock returns using fintech approaches

This study uses fintech approaches, including web crawler technology with distributed architecture to select internet news messages largely and efficiently and a dictionary-based linguistic text mining to create sentiment variables, to explore the respective impacts of investors' optimism and pessimism on stock returns. The construction of sentiment variables in network- and dictionary-based messages is more precise and variable than that in traditional-based messages. Our results show that firms with investors' optimistic sentiments have significantly higher stock returns in the current month, whereas those with pessimistic sentiments have significantly opposite effects. The effect of both investors' optimism and pessimism on stock returns subsequently reverses. Then, the negative impacts of investors' largely pessimistic sentiments on stock returns are larger than the positive impacts of their largely optimistic sentiments within a quarter. Next, investors' optimistic sentiments significantly raise stock return volatility by approximately a quarter, but their pessimistic sentiments have the opposite effects. Furthermore, investors' high optimism more significantly and persistently raises stock return volatility than their general optimism, but the negative effects of their high pessimism on volatility become smaller and the persistence is shorter than general pessimism. In addition to the advantage of our methodology in creating sentiment variables, the simultaneous consideration of investors' optimism and pessimism to analyze the effects on the returns and the volatility of individual stocks in this study is more complete than previous related studies.     

Kidnapped mutual funds: Irrational preference of naive investors and fund incentive distortion

This study documents that mutual fund investors in Chinese stock markets confuse factor-related returns (FRR) with active alpha. This revealed preference “kidnaps” mutual funds to chase FRR instead of alpha. The observed distorted incentive is intensified among less sophisticated groups as evidenced by investor type and fund-rating heterogeneity. Investors' biased skill assessment is irrational, even if FRR is a vital part of investors' utility function, as there is performance reversal for funds assessed as top performers. We further showed that a distorted incentive to chase FRR undermines mutual funds' willingness to generate alpha by combating fundamental mispricing. Mutual funds cater to investors' preferences by creating more speculative short-term factor timing and holding more lottery-like stocks. Our findings question the widely held belief of the sophisticated Bayesian-agent paradigm in household financial decision-making and cast doubt on institutions' willingness to address mispricing, as suggested by the efficient market hypothesis.     

Asset Float and Speculative Bubbles

We model the relationship between asset float (tradeable shares) and speculative bubbles. Investors with heterogeneous beliefs and short‐sales constraints trade a stock with limited float because of insider lockups. A bubble arises as price overweighs optimists' beliefs and investors anticipate the option to resell to those with even higher valuations. The bubble's size depends on float as investors anticipate an increase in float with lockup expirations and speculate over the degree of insider selling. Consistent with the internet experience, the bubble, turnover, and volatility decrease with float and prices drop on the lockup expiration date.     

Leverage Is a Double-Edged Sword

We use proprietary data on intraday transactions at a futures brokerage to analyze how implied leverage influences trading performance. Across all investors, leverage is negatively related to performance, due partly to increased trading costs and partly to forced liquidations resulting from margin calls. Defining skill out-of-sample, we find that relative performance differentials across unskilled and skilled investors persist. Unskilled investors' leverage amplifies losses from lottery preferences and the disposition effect. Leverage stimulates liquidity provision by skilled investors, and enhances returns. Although regulatory increases in required margins decrease skilled investors' returns, they enhance overall returns, and attenuate return volatility.     

How Do Investors' Expectations Drive Asset Prices?

Based on an extension of the process of investors' expectations to stochastic volatility we derive asset price processes in a general continuous time pricing kernel framework. Our analysis suggests that stochastic volatility of asset price processes results from the fact that investors do not know the risk of an asset and therefore the volatility of the process of their expectations is stochastic, too. Furthermore, our model is consistent with empirical studies reporting negative correlation between asset prices and their volatility as well as significant variations in the Sharpe ratio.     

Opening price manipulation and its value influences

We investigate how opening price manipulation influences market behaviors and investors' returns. Analyzing direct evidence comprising 87 opening price manipulation cases, and indirect evidence consisting of 19,003 suspected cases detected by an opening price manipulation identification model that we construct, we examine the impact of manipulation on mispricing, investors' welfare, trading activity and price volatility. Our results indicate that manipulated stocks experience significantly lower returns and a higher probability of price reversal after manipulation. Investors who purchase manipulated stocks at their opening price, or the volume-weighted average price, on the manipulation day make losses on their investments. Further, manipulation increases market trading activity and price volatility due to the influx of retail investors. Our additional analysis demonstrates that enhancing the intensity of external supervision and internal governance can mitigate mispricing caused by opening price manipulation. Our study provides novel evidence of the economic consequences of open market manipulation and policy implications for governments and regulators to develop effective supervisory processes to reduce manipulation and mitigate its impact on efficient markets.     

The diligent effect of investor relation officers in conference calls: Evidence from China

This study explores the determinants of investor relations (IR) officers’ diligence in conference calls and the impact of their diligence on capital markets. We apply IR officers' attendance in conference calls as a proxy variable for their diligence. We find that the age, gender, salary, and tenure of IR officers and the start time of conference calls are determinants of IR officers' diligence in conference calls. Their diligence significantly increases institutional ownership and reduces returns volatility. Further analysis shows that IR officers' diligence facilitates the growth of domestic institutional investors' ownership significantly more than that of foreign institutional investors. In addition, information transparency significantly facilitates the relationship between IR officers' diligence and return volatility. Finally, the change in institutional ownership and return volatility also varies with firm size and state ownership. In conclusion, we find that IR officers' diligence plays a positive role in IR management, as it significantly improves firms' institutional ownership and lowers return volatility.     

Investor ambiguity,systemic banking risk and economic activity: The case of too-big-to-fail

This paper examines the relationship between investors' ambiguity in the financial options market and systemic banks' risk. Eliciting ambiguity information from option pricing data on the twelve major U.S. banks between 2003 and 2010, we show that higher behavioral deviations from risk-neutral and Bayesian valuation (i.e., investor ambiguity) are associated with higher systemic banks' downside, market and credit risks. Consistent with behavioral explanations, we confirm the detrimental effect of ambiguity on financial market outcomes and find strong evidence of ambiguity among call and put option holders. Variance decomposition indicates that such a pattern of behavior explains a significant proportion of U.S. banking risk variance. This effect is more pronounced during periods of economic turbulence and bank stress (i.e., the 2007–2009 crisis), and holds after controlling for size, tail risk, implied volatility, and volatility of volatility dynamics. We also document that ambiguity from the financial market has a depressing impact on real economic activity, including capacity utilization, non-farm payrolls and overall economic performance. Our findings are robust to alternative specifications of ambiguity such as multiple priors and expected utilities with uncertain probabilities.     

The Dark Side of Circuit Breakers

Market-wide circuit breakers are trading halts aimed at stabilizing the market during dramatic price declines. Using an intertemporal equilibrium model, we show that a circuit breaker significantly alters market dynamics and affects investor welfare. As the market approaches the circuit breaker, price volatility rises drastically, accelerating the chance of triggering the circuit breaker—the so-called “magnet effect,” returns exhibit increasing negative skewness, and trading activity spikes up. Our empirical analysis supports the model's predictions. Circuit breakers can affect overall welfare negatively or positively, depending on the relative significance of investors' trading motives for risk sharing versus irrational speculation.     

The Differential Impact of Federal Reserve Margin Requirements on Stock Return Volatility

This study examines the effect of changes in margin requirements on stock price volatility. We examine the possibility that the impact of margin requirements varies with a stock's degree of speculative interest. Using four alternative measures of speculative interest, we divide our sample into ten portfolios. We find no consistent evidence of a relationship between margin requirements and changes in volatility for any portfolio. The inconsistent and often contradictory results produced by these changes question its usefulness by Federal Reserve decision makers.     

The impact of salient political and economic news on the trading activity

This paper investigates the impact of salient political and economic news on the intraday trading activity, namely, the stock return volatility, the stock price volatility, the number of shares traded, and the trading frequency. Using transactions data on 33 constituent stocks of the Hang Seng Index in the Stock Exchange of Hong Kong (SEHK), we find that political news has a distinct impact on market activity when compared with economic news. We argue that the observed phenomenon is related to the precision of signals associated with these two types of news and investors' perceptual biases.     

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.     

Stock market entry timing and retail investors' disposition effect

This paper explores the long-lasting impact of investors' first impression of participation in the stock market and the disposition effect. Using a unique dataset of account-level transaction records from a large brokerage firm in China, we find strong evidence for the existence of a disposition effect of Chinese retail investors. Our empirical results suggest that investors exhibit a stronger disposition effect if they initially participate in the stock market in periods of lower market returns, lower investor sentiment, higher market volatility, or higher economic policy uncertainty (EPU). The evidence enhances our understanding of the role of investors' early experience in stock market decisions and the determinants of behavioural biases in investment decisions.     

Stock Volatility and the Levels of the Basis and Open Interest in Futures Contracts

This article tests a theoretical model of the basis and open interest of stock index futures. The model is based on the differences between stock and futures in terms of investors' ability to customize stock portfolios and liquidity. Empirical evidence confirms the model's prediction that increased volatility decreases the basis and increases open interest.     

The volatility-confined LPPL model: A consistent model of ‘explosive’ financial bubbles with mean-reverting residuals

Using the concept of the stochastic discount factor with critical behavior, we present a self-consistent model for explosive financial bubbles, which combines a mean-reverting volatility process and a stochastic conditional return which reflects nonlinear positive feedbacks and continuous updates of the investors' beliefs and sentiments. The conditional expected returns exhibit faster-than-exponential acceleration decorated by accelerating oscillations, called “log-periodic power law” (LPPL). Tests on residuals show a remarkable, low rate (0.2%) of false positives when applied to a GARCH benchmark. When tested on the S&P500 US index from Jan. 3, 1950 to Nov. 21, 2008, the model correctly identifies the bubbles ending in Oct. 1987, in Oct. 1997, and in Aug. 1998 and the ITC bubble ending on the first quarter of 2000. Different unit-root tests confirm the high relevance of the model specification. Our model also provides a diagnostic for the duration of bubbles: applied to the period before the Oct. 1987 crash, there is clear evidence that the bubble started at least 4 years earlier. We confirm the validity and universality of the volatility-confined LPPL model on seven other major bubbles that have occurred in the World in the last two decades. Using Bayesian inference, we find a very strong statistical preference for our model compared with a standard benchmark, in contradiction with Chang and Feigenbaum (2006) which used a unit-root model for residuals.     

Trading behaviour and market sentiment: Firm-level evidence from an emerging Islamic market

We provide firm-level evidence from an emerging Islamic market that individual investors' trading behaviour causes weekend sentiment. Using data for 285 companies listed on the Dhaka Stock Exchange (DSE) for the period from 2002 to 2019 and applying appropriate econometric techniques, the paper has found evidence of weekend effect both on return and volatility. The results confirm that individual investors' sentiment drives the weekend effect in DSE. ‘Information content theory’ and ‘information processing hypothesis’ work for investors so that the market return and volatility become significantly different on Sunday. The market sentiment effect is significant for smaller firms and low dividend yield firms where individual investors are prevalent, suggesting that trading behaviour of individual investors determines weekend sentiment. A positive feedback relationship exists between returns on Sunday and the previous Thursday for both institutions and individuals. Our results are robust in various alternative specifications.     

Economic policy uncertainty exposure and stock price bubbles: Evidence from China

We explore the impact of economic policy uncertainty exposure (hereafter, EPU exposure) on stock price bubbles. We find that there exists a significantly positive relationship between EPU exposure and stock price bubbles. This result is still significant after a series of robustness checks. Moreover, the relationship between EPU exposure and bubbles is due to retail investors' speculative trading behavior. In addition, optimistic aggregate states and firms with higher information uncertainty characteristics strengthen the EPU exposure effects. Overall, we provide unique evidence regarding the impact of uncertainty on stock prices.     

Word-of-mouth communication,noise-driven volatility,and public disclosure

This paper examines how a firm adjusts its disclosure quality in response to technological innovations that improve investors' private information. We show that more precise private information can endogenously amplify supply shocks and, hence, increase noise-driven (or non-fundamental) price volatility. We study how the firm reacts to such changes and derive a necessary and sufficient condition under which the firm improves its disclosure quality when investors are informed with better private signals. We then apply our model to study investors' private word-of-mouth communication. Our analysis highlights a “dark side” of word-of-mouth communication and a call for better public disclosure even if private communication is assumed to be unbiased and truthful. We provide empirical predictions regarding how price volatility, market depth, and firms’ disclosure qualities would change as technological innovations, such as social media, facilitate information sharing among investors.     

The impact of religious practice on stock returns and volatility

With a psychological and behavioral perspective, this paper examines whether religious practice, through its influence on investors' moods and emotions, affect the behavior of the stock markets and investors in 15 Islamic countries over the period December 31, 2005 to December 31, 2015 and over four sub-periods (before and after both the global financial crisis and the Arab spring). The results indicate that volatility decreases during the month of Ramadan and is significantly different from the volatility observed in the other 11 months of the Islamic calendar year in most Muslim countries. We also identify that changes in stock returns and volatility during the month of Ramadan are related to religious practice and not due to the global financial crisis or the Arab spring. The findings significantly improve the understanding of the role of religious practice on stock market behavior and as such may be of great interest to investors and market regulators.     

The effectiveness of competing regulatory regimes and the switching effects: Evidence from an emerging market

I investigate the effectiveness of two competing regulatory regimes and the effect of switching from strict price limits to circuit breakers on volatility spillover, and also on trading interference hypotheses. I find that switching to the circuit breakers' regime increases volatility and disrupts the price discovery mechanism. Stock prices are prevented from reaching their equilibrium levels and traders are unable to obtain their desired positions on limits hit day. Moreover, I find that volatility is spread out over the following 2 days post-limit hits within the strict price limits regime. Finally, the results show that price limits interfere with trading activity and affect investors' beliefs and liquidity positions.