行为模型新解及其实证检验

在以信息逐步扩散和投资者有限理性为主要假设的行为模型中,特定信息交易者和市场信息交易者的比例对股价行为有着重要影响：当特定信息交易者占多数时,个股收益更容易呈现正自相关;当市场信息交易者占多数时,个股收益更容易呈现负自相关。该模型可以解释成熟股市中存在基于总收益的动量效应,而中国股市中不存在基于总收益的动量效应,仅存在基于公司特定收益的动量效应;并解释了市场平均收益呈现负自相关等。另外,实证分析支持了传统的CAPM和APT定价模型中的带越小,动量效应越显著的结论。     

Stock market volatility and equity returns: Evidence from a two-state Markov-switching model with regressors

This paper proposes a two-state Markov-switching model for stock market returns in which the state-dependent expected returns, their variance and associated regime-switching dynamics are allowed to respond to market information. More specifically, we apply this model to examine the explanatory and predictive power of price range and trading volume for return volatility. Our findings indicate that a negative relation between equity market returns and volatility prevails even after having controlled for the time-varying determinants of conditional volatility within each regime. We also find an asymmetry in the effect of price range on intra- and inter-regime return volatility. While price range has a stronger effect in the high volatility state, it appears to significantly affect only the transition probabilities when the stock market is in the low volatility state but not in the high volatility state. Finally, we provide evidence consistent with the ‘rebound’ model of asset returns proposed by Samuelson (1991), suggesting that long-horizon investors are expected to invest more in risky assets than short-horizon investors.     

Abnormal trading volume,news and market efficiency: Evidence from the Jamaica Stock Exchange

This paper investigates market efficiency of the Jamaica Stock Exchange (JSE). Together, weak and semi-strong form efficiency claim that historical and newly released public information do not predict future stock price movement. We test both forms of market efficiency by analyzing stock price behavior during times of abnormal trading volume and around the release dates of earnings information. Abnormal trading volume may be driven by liquidity demand or reflect new or private information flow to the market. Using JSE data over the period 2000 to 2021, we find price dynamics consistent with price pressure as firms experience negative abnormal returns on the day of abnormal trading activity but offsetting positive abnormal stock returns on the following day. Further findings show post earnings announcement drift on the JSE. Taken as a whole, the evidence suggests violations of market efficiency and has implications for capital allocation in this emerging market.     

Striking oil: Another puzzle?

Changes in oil prices predict stock market returns worldwide. We find significant predictability in both developed and emerging markets. These results cannot be explained by time-varying risk premia as oil price changes also significantly predict negative excess returns. Investors seem to underreact to information in the price of oil. A rise in oil prices drastically lowers future stock returns. Consistent with the hypothesis of a delayed reaction by investors, the relation between monthly stock returns and lagged monthly oil price changes strengthens once we introduce lags of several trading days between monthly stock returns and lagged monthly oil price changes.     

THE VALUATION EFFECTS OF OUT-OF-THE-MONEY CALLS OF CONVERTIBLE SECURITIES

We examine the valuation effects of out-of-the-money calls of convertible securities. In general, out-of-the-money calls generate positive abnormal stock returns. These returns are higher when the call price exceeds the market value of the called securities (positive premium calls), compared with when the market value exceeds the call price (negative premium calls). Furthermore, Value Line Investment Survey net operating income forecasts are significantly higher after call announcements for positive premium calls, while the revision is insignificant for negative premium calls. The results are consistent with the hypothesis that positive premium calls signal positive information.     

Search and herding effects in peer-to-peer lending: evidence from prosper.com

I examine loan data from Prosper.com—a website which allows borrowers to post loans and for lenders to bid on those loans. The Prosper market somewhat resembles the theoretical model of search, herding, and crowding in a large market described in Berkovich and Tayon (Phd. dissertation—Essays on search and herding. University of Pennsylvania, Pennsylvania, 2009). That model predicts that assets with high and low prices have high variance in the difference between price and true value. These extreme price regions of the asset-space are where private information provides excess returns. In the Prosper market, I find some evidence for the model since loans with low ex post returns show higher variance of the difference between price and ex post return. I also find that high-priced loans provide excess returns even after accounting for risk-aversion.     

The Informational Efficiency of the Equity Market As Compared to the Syndicated Bank Loan Market

The loan market is a hybrid between a public and a private market, comprised of financial institutions with access to private information about borrowing firms. We test whether this is reflected in informationally efficient price formation in the loan market vis-a-vis the equity markets, and reject this private information hypothesis. We also reject a liquidity hypothesis which suggests that equity markets always lead loan markets, despite bank lenders' access to private information, because of greater liquidity in equity markets. We further test, and reject, an asymmetric price reaction hypothesis that states that loan returns are more sensitive to negative information whereas equity returns respond symmetrically to both positive and negative information. We find evidence most consistent with an integrated markets hypothesis that suggests that both the equity and syndicated bank loan markets are highly integrated such that information flows freely across markets. This is particularly true when the equity market makers are also loan syndicate members.      

Does revenue momentum drive or ride earnings or price momentum?

This paper examines the profits of revenue, earnings, and price momentum strategies in an attempt to understand investor reactions when facing multiple information of firm performance in various scenarios. We first offer evidence that there is no dominating momentum strategy among the revenue, earnings, and price momentums, suggesting that revenue surprises, earnings surprises, and prior returns each carry some exclusive unpriced information content. We next show that the profits of momentum driven by firm fundamental performance information (revenue or earnings) depend upon the accompanying firm market performance information (price), and vice versa. The robust monotonicity in multivariate momentum returns is consistent with the argument that the market does not only underestimate the individual information but also the joint implications of multiple information on firm performance, particularly when they point in the same direction. A three-way combined momentum strategy may offer monthly return as high as 1.44%. The information conveyed by revenue surprises and earnings surprises combined account for about 19% of price momentum effects, which finding adds to the large literature on tracing the sources of price momentum.     

投资者情绪是导致我国投资者对市场信息出现反应偏差的原因吗：基于贝叶斯分位数回归模型的研究

本文使用贝叶斯分位数回归模型实证分析包含投资者情绪的投资者最优选择模型,结果表明：投资者情绪对于股票收益率存在非线性的正向影响,这是造成投资者对于市场信息出现反应偏差的一个重要原因.同时,市场信息和投资者情绪指标对于我国股票收益率都有着较大的影响作用;当股票出现不同涨跌幅时,市场信息对于股票收益率的影响有着较大的差异性.而考虑了投资者情绪指标之后,投资者对于市场信息的反应偏差明显减小,说明投资者情绪是造成我国投资者对于市场信息出现过度反应和反应不足的重要原因.我国投资者应该树立起良好的投资意识和心态,避免潜在的投资损失.     

The Timing of Opening Trades and Pricing Errors

After demonstrating that a zero investment trading strategy that buys stocks with overnight returns below the market average and sells stocks with overnight returns above the market average earns more than 1% monthly profit, I demonstrate that this profit is greater for stocks that start trading more quickly than for other stocks. These results control for trading costs. The resulting pricing errors are a material portion of stock price volatility and suggest that a quick response to overnight information adds non‐information‐based stock volatility to stock prices.     

Efficiency of the silver futures market: An empirical study using daily data

This paper investigates whether the silver futures market is efficient with respect to the information contained in the time series of daily price changes. An analysis of the serial correlation of returns on silver futures supports the hypothesis that successive price changes are independent. However, a series of first and second order Markov chain models built using the direction as well as the magnitude of price change, reveals some short-term dependence. This result regarding the non-independence of successive price changes is reinforced by an analysis of upward and downward cycles, and by the extraordinary profits generated by using mechanical filter rules. The conclusion of this study is that the silver futures market does not seem to be efficient even in the weak form and that astute traders and investors can make modest excess risk-adjusted returns by using appropriate trading strategies.     

The Relation between Stock Market Movements and NYSE Seat Prices

Exchange seat prices are widely reported and followed as measures of market sentiment. This paper analyzes the information content of NYSE seat prices using: (1) annual seat prices from 1869 to 1998, and (2) the complete record of trades, bids and offers for the seat market from 1973 to 1994. Seat market volumes have predictive power regarding future stock market returns, consistent with a model where seat market activity is a proxy for unobserved factors affecting expected returns. We find abnormally large price movements in seats prior to October 1987, consistent with the hypothesis that seat prices capture market sentiment.     

PRICE AND VOLUME EFFECTS ASSOCIATED WITH THE CREATION OF STANDARD & POOR'S MIDCAP INDEX

In this paper we explore price and volume effects associated with the 1991 creation of Standard & Poor's MidCap 400 index. Prior work on changes in the composition of existing indices finds a significant price response to the announcement. Various authors link the effect to price pressure, information, an outwardly shifting demand curve for securities, and the increased attention that comes with inclusion in an index. Using event study methodology, we find significant price and volume effects during the two weeks leading up to the Standard & Poor's announcement, but no significant effect in the two-day interval around the event. Apparently, information leakage and/or anticipation preceded the creation of the index. The price run-up is permanent since the positive abnormal returns leading up through the announcement are not associated with significantly negative abnormal returns after the announcement. In addition, MidCap stocks significantly outperform the market during the fifty-two weeks following the announcement. Using cross-sectional regressions, we show that these prior-period abnormal returns are positively related to abnormal volume and institutional holdings. We also find that firms trading over-the-counter had larger price run-ups than NYSE or AMEX firms.     

Oil and stock market activity when prices go up and down: the case of the oil and gas industry

We examine the asymmetric effects of daily oil price changes on equity returns, market betas, oil betas, return variances, and trading volumes for the US oil and gas industry. The responses of stock returns associated with negative changes in oil prices are higher than that associated with positive changes in oil prices. Stock risk measured by market beta is influenced more due to oil price decreases than due to oil price increases. On the other hand, oil risk exposures (oil betas) and return variances are more influenced by oil price increases than oil price decreases. The results of our study indicate that oil and gas firm returns, market betas, oil betas, return variances respond asymmetrically to oil price changes. We also find that relative changes in oil prices along with firm-specific factors such as firm size, ROA, leverage, market-to-book ratio (MBR) are important in determining the effects of oil price changes on oil and gas firms’ returns, risks, and trading volumes.     

Internet search intensity,liquidity and returns in emerging markets

Using a sample of listed companies in the Vietnam stock market from 2013 to 2018, this paper investigates the linkage between Internet search intenseness and stock returns and trading volume. The empirical results confirm the “price pressure hypothesis” that search intensity is positively associated with subsequent stock returns and trading volume. It also finds that the positive effects on stock returns are not temporary but remain for the long term although some reversals occur. The results show that the effects of search intensity on stock returns are higher for large stocks than for small stocks. The findings also reveal that stocks that attract more attention from the public are exposed to higher market risk. These findings have not been documented in the literature so they enrich the information on the relationship between Internet search intenseness and stock market returns, especially for emerging markets where Internet user numbers are sharply increasing.     

Dynamics of Asset Prices and Transaction Activity in Illiquid Markets: the Case of Private Commercial Real Estate

This paper investigates the relationship between capital flows, turnover and returns for the UK private real estate market. We examine a number of possible implications of capital flows and turnover on capital returns testing for evidence of a price pressure effect, ‘return chasing’ behaviour and information revelation. The main tool of analysis is a panel vector autoregressive (VAR) regression model in which institutional capital flows, turnover and returns are specified as endogenous variables in a two equation system in which we also control for macro-economic variables. Data on flows, turnover and returns are obtained for the ten market segments covering the main UK commercial real estate sectors. Our results do not support the widely-held belief among practitioners that capital flows have a ‘price pressure’ effect on property prices. However, we do find a significant positive relationship between lagged turnover and contemporaneous capital returns, suggesting that asset turnover provides increased price revelation which, in turn, reduces investment risk and increases property values.     

Are corporate managers savvy about their stock price? Evidence from insider trading after earnings announcements

We find that insiders trade as if they exploit market underreaction to earnings news, buying (selling) after good (bad) earnings announcements when the price reaction to the announcement is low (high). We also find that insider trades attributable to public information about earnings and the price reaction generate abnormal returns. By demonstrating that managers spot market underreaction to earnings news, our results imply that managers are savvy about their company’s stock price.     

Momentum Strategies

We examine whether the predictability of future returns from past returns is due to the market's underreaction to information, in particular to past earnings news. Past return and past earnings surprise each predict large drifts in future returns after controlling for the other. Market risk, size, and book–to–market effects do not explain the drifts. There is little evidence of subsequent reversals in the returns of stocks with high price and earnings momentum. Security analysts' earnings forecasts also respond sluggishly to past news, especially in the case of stocks with the worst past performance. The results suggest a market that responds only gradually to new information.     

Stock prices and the flow of information in the Athens Stock Exchange

The paper investigates the dynamics of price changes and information flow to the market in the Athens Stock Exchange in Greece using daily data over the period 1988 to 1993. A generalised autoregressive conditional heteroskedastic (GARCH) model in stock returns is shown to reflect time dependence in the process generating information flow to the market. Using daily trading volume or value as proxies for information flow, we find them to be significant in explaining the variance of daily returns and to reduce GARCH effects substantially. This has implications for the informational efficiency of the market.     

Asymmetric Price and Volatility Adjustments in Emerging Asian Stock Markets

This paper tests the hypothesis that stock returns in emerging stock markets adjust asymmetrically to past information. The evidence suggests that both the conditional mean and the conditional variance respond asymmetrically to past information. In agreement with studies dealing with developed stock markets, the conditional variance is an asymmetrical function of past innovations, rising proportionately more during market declines. More importantly, the conditional mean is also an asymmetrical function of past returns. Specifically, positive past returns are more persistent than negative past returns of an equal magnitude. This behaviour is consistent with an asymmetric partial adjustment price model where news suggesting overpricing (negative returns) are incorporated faster into current prices than news suggesting underpricing (positive returns). Furthermore, the asymmetric adjustment of prices to past information could be partially responsible for the asymmetries in the conditional variance if the degree of adjustment and the level of volatility are positively related.