投资者非理性行为是动量效应产生的原因吗?——来自互联网金融论坛的证据

动量效应是行为金融研究中重要的市场异象,然而目前各市场因素并不能完全解释其来源。在大数据背景下,本文通过挖掘金融论坛的结构化和非结构化数据,深入研究投资者微观行为与动量效应的关系,发现市值规模、账面市值比和行业等市场因素仅能解释约30%的动量效应,而基于行为金融的投资者非理性因素——投资者情绪、投资者关注度和情绪传播度,都是动量效应形成的重要因素,在市场因素的基础上还能继续解释35%左右的动量效应。研究结论对理解动量效应的形成机制和投资实践中网络信息的价值有重要意义。     

媒体报道与IPO绩效:信息不对称还是投资者情绪?——基于创业板上市公司的研究

本文以创业板开板以来至2011年4月底的所有创业板IPO公司为研究样本,通过讨论IPO前不同时期的媒体报道情况对IPO绩效的影响,探讨了媒体在IPO过程中所扮演的角色。在控制样本自选择偏差后,发现招股公告日至上市日之间的短期媒体报道与IPO抑价和首日换手率均呈显著的正相关关系,符合投资者情绪假说;而招股公告日前一年的长期媒体报道与IPO抑价也显著正相关,但是和首日换手率之间的关系并不显著,信息不对称假说未得到支持。本文认为信息不对称假说未得到支持可能与市场以情绪投资为主、忽视价值投资的现象有关。     

Investor sentiment and the risk–return relation: A two-in-one approach

Traditional finance theory posits a positive risk–return relation, but empirical evidence is inconclusive. Retail investor sentiment has long been viewed as a distorting factor, while more recently institutional investor sentiment is thought to play a role. We examine the separate and joint impacts of retail and institutional investor sentiments on the risk-return relation. We find, at both market and firm levels, the risk-return relation is more likely to be distorted by the two investor-type sentiments jointly, rather than separately. We further find a cross-sectional pattern, with the risk-return relation being more sensitive to investor sentiment for stocks with specific characteristics.     

Are Happy Investors Likely to Be Overconfident?

This study investigates the relationship of investors' happy sentiment and overconfidence effect. Sunshine, temperature, former returns, and margin loan change rate are used as proxies for happy sentiment. Using data from Taiwan Stock Exchange and principal component analysis, the happy sentiment index is divided into two categories: "natural environment happiness" and "investment atmosphere happiness." The results suggest that when natural environment happiness is stronger, investors are less likely to have overconfidence. On the contrary, when investment atmosphere happiness is stronger, investors are more likely to have overconfidence.     

Post-IPO Operating Performance, Venture Capital and the Bubble Years

Abstract:  We analyse the post-issue operating performance of 316 venture-backed and 274 non-venture UK IPOs 1985–2003. The finding of a statistically significant five-year, operational decline exhibited over the full sample period is not robust. Rather it is driven by the dramatic underperformance during the 1998–2000 bubble years while IPOs perform normally in the remaining years. Cross-section regression results indicate support for venture capital certification in the non-bubble years but a significantly negative relationship between operating performance and venture capitalist board representation during the bubble years. The bubble year underperformance is explained by market timing and by low quality companies taking advantage of investor sentiment.     

Does Investor Sentiment Affect Earnings Management?

I hypothesize and find that earnings management via accruals is driven partially by the prevailing market‐wide investor sentiment. Managers inflate earnings in periods of higher sentiment, but report more conservatively during periods of low sentiment. Moreover, the likelihood of income‐increasing earnings management to avoid negative earnings surprises is also positively associated with investor sentiment. These results are robust to: (i) controls for time‐varying firm characteristics such as growth, investment opportunity sets, future profitability, leverage and size; (ii) macroeconomic variables such as future inflation, GDP growth, and growth in industrial production; (iii) multiple proxies for investor sentiment; and (iv) discretionary revenues as alternative measure of earnings management. Cross‐sectional analyses reveal that firms whose stock returns co‐move more with investor sentiment are more (less) likely to manage earnings upward via abnormal accruals in quarters of higher (lower) sentiment. The findings of managers’ strategic use of abnormal accruals show the need for increased attention from boards of directors, auditors and regulators to heightened managerial incentives to overstate earnings and to report optimistic earnings numbers during periods of high investor sentiment.     

Futures Market Sentiment and Institutional Investor Behavior in the Spot Market: The Emerging Market in Taiwan

This paper investigates whether and how futures market sentiment and stock market returns heterogeneously affect the trading activities of institutional investors in the spot market in Taiwan. Our empirical results suggest that foreign investors are net sellers whenever futures market sentiment is bullish and net buyers when investor sentiment is bearish. The two types of domestic institutional investors have poor sentiment timing abilities and the price-pressure effect may account for the behavioral differences among institutional investors. In addition, all three institutional investors are momentum traders. Nevertheless, the momentum trading of foreigners is consistent with an information-based model and that of two local institutional investors, as behavior-based models suggest. This indicates that the same trading momentum strategy can lead to different outcomes for different investors, and both information- and behavior-based momentum trading can exist contemporaneously in the Taiwanese stock market.     

投资者关注与股价崩盘风险:抑制还是加剧?

本文以2010—2017年中国A股上市公司为样本,考察了投资者关注影响股价崩盘风险的客观表现和传导路径。研究发现,投资者关注度的提高会显著加剧下一期的股价崩盘风险,存在“关注度的崩盘效应”;分组检验发现,关注度的崩盘效应仅在机构持股比例低的公司和市场处于牛市状态下存在;路径检验发现,投资者关注不存在信息路径,没有改善公司信息透明度,但存在部分的情绪路径,提高了股价同步性和投资者情绪,从而加剧了股价崩盘风险。建议监管部门重视投资者关注对股价带来的冲击,通过进一步提高机构者持股比例,缓解情绪过热导致的定价错误程度,降低股价崩盘风险。     

Investor Sentiment and Stock Returns: Evidence from Turkey

This paper investigates the relation between investor sentiment and stock returns on the Istanbul Stock Exchange, employing vector autoregressive (VAR) analysis and Granger causality tests. The sample period extends from July 1997 to June 2005. In the VAR models, stock portfolio returns and investor sentiment proxies are used as endogenous variables. Two dummy variables accounting for natural and economic crises are used as exogenous variables. The analysis results suggest that, excepting shares of equity issues in aggregate issues, stock portfolio returns seem to affect all investor sentiment proxies, namely closed-end fund discount, mutual fund flows, odd-lot sales-to-purchases ratio, and repo holdings of mutual funds. Investor sentiment does not appear to forecast future stock returns; only the turnover ratio of the stock market seems to have forecasting potential.     

Investor Trading Behavior and Sentiment in Futures Markets

This study investigates the effects of investor trading behavior and investor sentiment on futures market return. We find that the spot investor trading behavior, futures investor trading behavior, spot market sentiment, and futures market sentiment all have positive effects on daily futures returns in Chinese financial market. More importantly, we show that the effect of (spot) futures investor trading behavior has better explanatory power than (spot) futures market sentiment on futures returns. Further supporting our results, high investor trading behavior and high investor sentiment strengthen the positive relation between sentiment-returns and behavior-returns.     

Managerial Placement and Entrenchment

Using data on companies that have implemented private placements in China from 2011 to 2016, we examine the discount on private placements, short-term stock returns, and long-term performance after the placements. Our goal is to determine whether the prevailing certification and entrenchment hypotheses can explain managerial placements. We find that the participation of managerial investors has a significant and negative impact on short-term stock returns. Such a negative effect can also be found on issuing companies’ long-term profitability. Moreover, managerial placements have a higher discount than nonmanagerial placements. Our findings suggest that managerial placement is consistent with the entrenchment hypothesis but not the certification hypothesis.     

投资者情绪与中国股票市场过度波动

本文分析中国投资者分类情绪及信心变化与中国股票市场波动的同期及动态影响。实证结果表明:就同期而言,中国投资者对国内经济基本面的信心变化以及中国股票市场波动,将影响投资者对国际经济金融环境的信心;就中长期而言,中国投资者情绪中关于国内经济基本面和国内经济政策的信心变化是影响中国股票市场过度波动的重要原因;中国投资者关于国际经济金融环境的信心深受国内经济基本面的信心变化的影响,中国投资者对A股市场估值的判断,受投资者对A股市场的股票估值信心以及国内经济基本面信心变化影响较大。