股票收益率可预测问题研究

本文运用均值回归理论对股票收益的可预测性问题进行了分析与研究,并使用自相关检验分别对具有代表性的六大股价指数进行了实证研究.得出了股票收益率短期呈随机漫步,长期收益率呈均值回归的基本结论,对长线投资者具有重要的参考价值.     

新三板做市商制度、股票流动性与证券价值北大核心CSSCISSCI

本文研究了新三板挂牌公司的股票转让方式由协议转让变更为做市转让对股票流动性和证券价值的影响。研究发现,一是与对照组公司的均值比较和基于倍差法模型的回归结果表明,实施了做市转让方式的处理组公司的股票流动性更高;二是处理组公司在事件日前后存在显著为正的平均累积异常收益,而这一现象在对照组公司中不存在;三是交易机制变更的个股的累积异常收益率与股票流动性变化正相关,控制样本选择偏差后的结论基本不变;四是交易机制变更的个股的股票流动性变化与做市商数量正相关,控制样本选择偏差后的结论基本不变。研究结果表明,做市商制度对股票流动性和证券价值有正面影响,我们不能因新三板市场整体换手率的波动而否定做市商制度的作用。     

两个证券组合模型的实证比较

本文随机选取沪深300中的十只股票为例,对证券投资组合的均值-方差模型(MV)和最小二阶矩模型进行了实证比较.计算分析发现,最小二阶矩模型比MV模型具有更好的业绩表现.     

沪市股票收益率特征实证分析

从现代投资组合理论出发,结合国内外的研究,使用上海证券交易所挂牌交易的103支股票2001-2005年期间的日收益率数据,在传统的时间序列回归分析和横截面回归分析的基础上,分析了这一时期股票的收益率特征。得出的结论是,在此期间,①可以使用市场模型来描述证券的收益产生过程;②市场模型的截距α值能够解释各股票期望收益率的差异;③在α值相等的条件下,股票的β值(风险)较高的股票其收益率会较低,即风险的市场价格为负值;④总的来看β值不能很好地解释股票的收益率差异,即CAPM是不成立的。     

基于均值——方差模型的云南特色股票研究

Markowitz均值——方差模型是用于研究投资者如何通过合理的资金分配来达到既定收益下,风险最小化问题.本文采用该模型,基于投资优化组合的理论对云南省内地的特色股票做投资组合分析,通过对五支股票数据的统计分析,得到在预期收益既定的条件下,投资风险最小时的最优投资组合。同时,根据这五支股票的投资权重进一步精选出三支股票,并计算出了最优的投资权重。     

样本时间跨度对CAPM适用性的影响

本文通过对上海证券市场中随机抽取的72支股票的数据分别在30天,120天,240天,3年,5年五个不同跨度的时间区间内做回归分析,分别检验资本资产定价理论在中国证券市场的有效性。得出了capm在样本时间区间跨度较小的情况下有效性较高,在样本时间区间跨度较大的情况下有效性则较低。且存在较大的非系统风险对股票收益率产生影响的结论。     

会计信息对股票市场解释能力的实证分析

近年来,西方学者对会计信息与股票市场的关系进行了大量的实证研究,证实会计收益与股票收益有很强的正相关关系,并进一步对现金流量指标是否具有增量信息展开了讨论。我国的情况如何?本文从实证的角度分析会计收益、现金流量指标与股票收益之间的关系,结果显示我国的会计收益与股票收益高度相关,现金流量也对股票收益具有解释能力;综合会计收益与现金流量指标的多元回归模型优于一元回归模型;拟合程度随着时间间隔的扩大而提高。     

经理股票期权与马克思劳动价值论的丰富和发展

<正>经理股票期权制度提出了劳动价值论和分配理论研究的新课题,它引发人们对马克思主义劳动价值理论以及"按劳分配"原则的深层思考。经理人力资本理论拓展了马克思主义劳动价值学说;推行股票期权制度进一步体现价值创造与价值分配的统一,这使马克思主义劳动价值论更具有了现实的说服力;经理股票期权体现了按劳分配与按资分配的有机结合,丰富和发展了马克思主义劳动价值论,是劳动价值论在社会主义     

股票随机模型及其衍生品期权定价理论研究

基于相关理论研究,并结合近几年在金融衍生品特别是期权定价方面的研究成果,利用随机分析理论,在股票混合过程的随机模型下,给出带有特殊股票红利支付的欧式看跌期权的定价公式,进而对金融衍生品定价的前景进行展望。     

中国股市个股非流动性、换手率和短期反转的关系

本文在排除买卖报价反弹、周末效应等干扰因素的前提下,利用分组构建逆势投资组合及Fama-Macbeth回归方法,研究周期下我国股市中的短期收益反转现象。实证结果表明：我国股市中存在短期收益反转现象,短期反转在股票输家中表现更为明显;股票收益的短期反转随着非流动性的增强而增强;我国股市具有极高换手率的投资组合表现出特殊性,极高换手率对股票输家的短期收益反转具有抑制作用,而对股票赢家的短期收益反转具有促进作用。     

EQUITY VALUATION EFFECTS OF WARRANT-DEBT FINANCING

Stock price reactions to warrant-debt unit financing announcements are examined and a significant two-day average abnormal return of ?1.32 percent is found. The negative average abnormal return is similar to that observed for convertible debt financing announcements in previous research. Warrant-debt financing decisions result in large increases in capitalization; on average, issuers' long-term debt increases by 84 percent, and common shares outstanding increase by 18 percent assuming full exercise of the warrants.     

An Option-Theoretic Approach to the Valuation of Dividend Reinvestment and Voluntary Purchase Plans

Many firms with dividend reinvestment plans also allow their shareholders to voluntarily invest supplemental funds to purchase additional shares. The purchase price for newly-issued shares often is determined by the average stock price over a prespecified time period preceding the investment date. This gives the firm's shareholders an option to invest in additional shares only when the stock price exceeds the computed average. This paper uses both theoretical and numerical methods to analyze the value of these voluntary purchase options in theory and practice.     

The pricing of U.S. IPOs by seasoned foreign firms

We examine the pricing of U.S. initial public offerings (IPOs) by foreign firms that are already seasoned in their domestic countries. Presumably, these equity offers have less downside risk for investors than typical IPOs since domestic share prices can be used to help establish a preoffer value for the firm's equity. In spite of the presumed diminished downside risk, we find that offers by firms from countries that impose foreign ownership restrictions and capital controls are on average underpriced, experiencing an average first-day return in the United States of 12.7%. This result stems in part from the underwriter's failure to price the issue to fully reflect the postoffer premium that often arises for the U.S. shares. In contrast, offers by firms from countries without ownership restrictions have an average first-day return of 0.0%.     

Share price performance following actual share repurchases

Using unique actual daily share repurchase data from Hong Kong, this paper investigates share price performance surrounding and following actual share repurchases. It is found that repurchasing firms buy back shares following price drops, suggesting that they behave opportunistically when implementing actual share repurchases. On average, the initial 3-day market response to actual repurchases is about 0.43%. Repurchasing firms do not seem to exhibit superior abnormal performance over long horizons when they make actual share repurchases. However, the price performance of repurchasing firms varies across firm size and market–book value ratios, and shows a clear and consistent pattern. The market responds the most favorably to repurchases that are made by small and value (high book-to-market value) firms. Over a long horizon, there is some evidence that repurchases made by value firms show superior performance. The three-year buy-and-hold abnormal return, which is measured against a portfolio of control firms that are matched by size and book-to-market value ratios, is over 20%. At least, repurchases made by high book-to-market value firms, for which undervaluation is more likely to occur, can benefit long-term shareholders.     

THE SIZE EFFECT IS PRIMARILY A PRICE EFFECT

Previous research shows that stock returns are related to firm market value and earnings yield. This study decomposes the measurements of market value and earnings yield into separate components (share price and shares outstanding for market value, earnings per share and share price for earnings yield) and examines the relationship between stock return and these components. Share price represents approximately three-fourths of the relationship between stock returns and either market value or earnings yield. Potential causes for this phenomenon are advanced.     

An Empirical Evaluation of an Induced Theory of Financial Ratios

The recent paper of Tippett (1990) explores some analytical properties of accounting ratios on the assumption that the underlying financial aggregates are generated by some form of diffusion process. The present paper uses a long time series of four accounting ratios, taken from the Cambridge/DTI database of the accounts of UK listed companies, to assess whether the models advanced in this paper can be sustained at an empirical level. Of the models tested, only the Logarithmic Random Walk and the Elastic Random Walk, seem to be consistent with the data. Even here, however, there is some evidence that the constant variance (homoscedasticity) assumption may not be satisfied and there is also a suggestion that the normality assumption might not be satisfied by the Elastic Random Walk models. Nonetheless, these models perform as well, if not better, than any of the models previously examined in the literature.     

Stock Returns and Volatility under Market Segmentation: The Case of Chinese A and B Shares

In most countries where firms list separate shares for trading by foreign and domestic investors, the prices of the foreign shares tend to be higher. In China, the reverse tends to be true. In this paper, we would like to focus on the information content in lagged premiums of Chinese A over B traded shares. The lagged premiums are found to have certain predictive power over the future returns and volatility of both A and B shares, with some interesting patterns. Specifically, an increase in the premium ratio of A shares will be followed by a rise in the return of A shares and a fall in the return of B shares. It is found that both of the investors in Chinese A- and B-share markets reveal positive feedback trading behavior. Moreover, the liquidity and information availability will affect the magnitude of such behavior especially in B-share markets. By using multivariate GARCH model, it is also demonstrated that the unexpected changes in the premium ratio of A-share price over B-share price contribute to the return volatility of both A shares and B shares. These patterns may provide foundations for the development of pricing models for equity shares under market segmentation.     

Do Corporate Managers Know When Their Shares Are Undervalued? New Evidence Based on Actual (and Not Just Announced) Stock Buybacks

This article summarizes the findings of the authors' recent study, published in the Journal of Financial Economics, of whether public companies are able to repurchase their own shares at a discount to the market, thereby earning more than a market return on such “investments.” To the extent the answer is yes, it would suggest that management has an advantage in assessing the intrinsic value of the companies they manage. Using as their sample all 2,237 publicly traded U.S. companies that repurchased their own stock between 2004 and 2011, the authors compared the average price paid during the month to the average price at which the firm's shares traded during that month as well as three and six months after the repurchase. (All earlier studies had measured stock performance from the date of the repurchase announcements rather than from the date of the actual repurchases.) The authors' conclusion, which may come as more of a surprise to financial economists than practicing corporate executives, was that the majority of companies repurchasing their shares have in fact earned a positive return on their investment in their own stock. Perhaps the most important finding of the study, however, was that infrequent repurchasers—defined as companies that bought back their own stock four or fewer times a year—have been much more successful in buying undervalued shares than regular repurchasers. For example, when evaluated over a six‐month holding period, the annual “alpha” of infrequent repurchasers was 2.4% greater than that of frequent repurchasers—those that bought back their shares at least nine times a year. And this advantage was even more significant for companies that repurchased just once during the year—a group that recorded an alpha of 5.9%, as compared to 1.5% for monthly repurchasers. Moreover, the results were essentially the same when extended over considerably longer holding periods. For the entire sample of companies that repurchased their shares, the authors reported finding positive and significant alphas of 0.3% per month over windows ranging from three months to three years after the repurchase. But, as reported above, the infrequent repurchasers significantly outperformed frequent repurchasers over all time horizons, with differences in alpha that ranged from a low of 0.3% and to as high as 0.6% per month.     

The Dog that Did Not Bark: Limited Price Efficiency and Strategic Nondisclosure

Theory posits that investors can rationally infer the implications of strategic nondisclosure for firm value, pressuring managers to disclose information voluntarily. This study documents that the lack of an earnings guidance predicts an abnormal return of −41 basis points around the subsequent quarterly earnings announcement, suggesting that investors do not fully incorporate the implications of nonguidance. Further analyses demonstrate that limitations in price efficiency, driven by investors' limited attention and short-selling constraints, explain the mispricing of nonguidance and are associated with less guidance issuance. Our results collectively highlight limited price efficiency as another friction when studying managers' strategic disclosure decisions.     

Time-Varying Betas of German Stock Returns

The market model assumes stock returns to be a linear function of the market return. However, there is considerable evidence that the beta stability assumption commonly used when estimating the market model is invalid. In this paper we account for beta instability in German stock returns by allowing the coefficients to vary over time in estimation. For time-varying beta estimation we rely on the Flexible Least Squares approach, the Random Walk Model and Moving Window Least Squares. Due to our results time-varying estimation fits the data considerably better than time-invariant estimation and, hence, increases the efficiency of beta based risk measurement.Acknowledgements: The authors thank Stefan Mittnik, Christian Pigorsch, an anonymous referee and the editor for constructive comments.