隐性杠杆约束、流动性风险和投资者情绪

本文以2003—2019年间开放式主动管理型的股票型和偏股型基金为样本,以持仓占比为权重估算基金投组中A股的总市场风险暴露,检验结果表明,该序列上升反映了基金面临的隐性杠杆约束收紧,刻画了市场的弱流动性。内在逻辑在于,流动性收紧时,投资者难以通过融资直接增加杠杆,更倾向于重仓持有高市场风险头寸的股票而间接实现杠杆。本文发现隐性杠杆约束所刻画的风险在股票或基金收益截面上的无条件定价基本失效,而条件定价则依赖于低市场情绪与弱流动性。分解基金持股的敞口,进一步发现,因中小盘基金在流动性收紧时具有更强的流动性偏好,其持股的市场风险头寸能够更敏锐地捕捉到弱流动性风险。     

Delayed Reaction to Good News and the Cross-Autocorrelation of Portfolio Returns

We document a directional asymmetry in the small stock concurrent and lagged response to large stock movements. When returns on large stocks are negative, the concurrent beta for small stocks is high, but the lagged beta is insignificant. When returns on large stocks are positive, small stocks have small concurrent betas and very significant lagged betas. That is, the cross-autocorrelation puzzle documented by Lo and MacKinlay (1990a) is associated with a slow response by some small stocks to good, but not to bad, common news. Time series portfolio tests and cross-sectional tests of the delay for individual securities suggest that existing explanations of the cross-autocorrelation puzzle based on data mismeasurement, minor market imperfections, or time-varying risk premiums fail to capture the directional asymmetry in the data.     

Accrual quality,skill, and the cross-section of mutual fund returns

We use returns of actively managed mutual funds to document the link between accrual quality (AQ) and systematic (priced) risk. Despite compelling theoretical arguments, prior research finds no evidence that poor AQ commands a risk premium in the cross-section of realized stock returns. We argue that the previously obtained premium estimates are biased downward because, for a large portion of poor AQ stocks, higher expected returns are offset by the news of deteriorating fundamentals. We suggest that skilled mutual fund managers should be able to either avoid investing in stocks with deteriorating fundamentals or assign them lower portfolio weights. As a consequence, returns on their portfolios should better reflect the expected AQ risk premium. Our empirical evidence is consistent with these predictions.     

Investor climate sentiment and financial markets

We propose to measure investor climate sentiment by performing sentiment analysis on StockTwits posts on climate change and global warming. In financial markets, stocks of emission (carbon-intensive) firms underperform clean (low-emission) stocks when investor climate sentiment is more positive. We document investors overreaction to climate change risk and reversal in longer horizons. Salient but uninformative climate change events, such as the release of a report on climate change and abnormal weather events, facilitate the investor learning process and correction of the mispricing.     

Closed-end funds and sentiment risk

Irradional noise traders earn high returns for bearing risk that they themselves create. Diversifying across closed-end funds does little to reduce this risk, because discounts are correlated across funds. But diversification between closed-end funds and large-cap stocks does reduce this risk, especially when markets are not subject to major shocks: a combination of closed-end funds and large-cap stocks has lower risk than either one alone. To the extent that fund shares and large-cap stocks are partially segmented markets, large-cap stocks thus provide some protection against the sentiment risk created by noise traders. This paper estimates the amount of large-cap stocks needed in tax-deferred portfolios, under various amounts of market-wide risk, and ways of measuring it.     

我国社保基金持股偏好研究

社保基金在证券市场上的投资表现会直接影响其运行的稳定性,由于其资金来源的特殊性,社保基金对于选择投资对象有没有明显的偏好呢？本文利用2008—2018年我国A股上市公司的数据,研究社保基金的持股偏好。研究表明,社保基金在进行投资时对于经营业绩好、风险性低、股权集中度高、估值偏低的股票具有明显的偏好。进一步研究发现,与保险公司偏好股权集中度低的股票、公募基金偏好流动性高的股票相比,社保基金更偏好股权集中度高的股票,而对于流动性高的股票并没有明显的偏好。     

我国基金重仓股选股偏好的时期似无关回归分析

基于基金重仓股季度面板数据,本文采用时期似无关回归模型分析了四大类共28个指标对基金持股比例的影响,并利用基金重仓股的统计值特点发现基金筛选股票的标准。研究结果表明,基金确实在寻求价值型投资,扩大基金规模可减轻股市投机行为;基金在调研阶段和操盘阶段对风险有不同的偏好,调研阶段规避风险,操盘阶段偏好高风险高回报;基金偏爱长期流动性好的股票;开放式基金的选股要求高于封闭式基金,牛市时基金的选股要求高于熊市;基金偏爱关注率高、信息丰富的股票;基金对行业的偏好基于行业的业绩表现;基金重仓股持股比例基本上与指数有相似的变化趋势。     

Short-sale constraints and informational efficiency to private information: A natural experiment

Exploiting a regulatory change in short-sale constraints (Regulation SHO) as a natural experiment, this paper examines the effect of short-sale constraints on informational efficiency of stock prices to private information. I find that short-sellers act as informed traders prior to forthcoming analyst news and trade on negative private information. When short-sale constraints are relaxed for pilot stocks (treatment group), both trading volume and stock price sensitivity increase prior to the analyst announcement for bad news but not for good news, relative to that of nonpilot stocks (control group). The findings are consistent with the Diamond and Verrecchia model that predicts that short-selling increases the speed of adjustment of stock prices to private negative information. In the cross-section, the effect of Reg SHO is stronger in stocks of firms with weak and uncertain information environments (i.e., small firms and firms with high analyst forecast dispersion).     

Leverage constraints and asset prices: Insights from mutual fund risk taking

Prior theory suggests that time variation in the degree to which leverage constraints bind affects the pricing kernel. We propose a measure for this leverage constraint tightness by inverting the argument that constrained investors tilt their portfolios to riskier assets. We show that the average market beta of actively managed mutual funds—intermediaries facing leverage restrictions—captures their desire for leverage and thus the tightness of constraints. Consistent with theory, it strongly predicts returns of the betting-against-beta portfolio, and is a priced risk factor in the cross-section of mutual funds and stocks. Funds with low exposure to the factor outperform high-exposure funds by 5% annually, and for stocks this difference reaches 7%. Our results show that the tightness of leverage constraints has important implications for asset prices.     

Index tracking and beta arbitrage effects in comovement

This paper develops a stylised model for S&P 500 index changes with two beta-based styles: index trackers and beta arbitrageurs who trade in both high and low beta event stocks to exploit mean reversion towards one. Arbitrageurs engage in common or contrarian trading patterns relative to index funds depending on whether historical betas are below or above one. Thus, the overall comovement effect has two distinct components. After index additions, pre-event low beta stocks drive the overall beta increases due to common demand – albeit for different reasons - from indexers and arbitrageurs. By contrast, arbitrageur shorting of high beta additions diminishes or sometimes reverses the beta increases for these stocks driven by indexers. Analogous results hold for index deletions.     

Stochastic portfolio theory and the low beta anomaly

Many studies have found that portfolios of low beta stocks have higher growth rates than portfolios of high beta stocks and have concluded that low beta stocks have higher growth rates than high beta stocks. Since rational investor behavior is thought to imply that additional risk is rewarded with additional return, the alleged higher growth rates of low beta versus high beta stocks has been termed a ‘Low Beta Anomaly’ (LBA). However, it is premature to conclude that these observed LBAs are due to stocks’ differential growth rates, because the tested portfolios are traded. Stochastic Portfolio Theory (SPT) shows that traded portfolios’ growth rates can exceed the growth rates of their stocks. This paper presents several SPT models of an LBA that do not require investment constraints, irrational investor behavior, or that low beta stocks have higher growth rates than high beta stocks. These LBAs are due to reconstitution relative volatility capture that favors portfolios of low vs. high beta stocks. They result from trading profit, not differential growth rates between low and high beta stocks. Monte Carlo simulations demonstrate a reconstitution relative volatility capture LBA that is consistent with the models and the literature.     

AUTOCORRELATION IN MARKET MODEL RESIDUALS

Autocorrelation in market model residuals affects the estimate of market risk measured by beta. Correction for autocorrelation can substantially change the estimate of beta for some common stocks. In view of the importance of beta estimates in financial research and investment practice, an examination is undertaken in this paper of the prevalence of autocorrelation and two of its causes. The evidence indicates that negative autocorrelation affects estimates of beta for a large number of stocks. In addition, negative autocorrelation is most prevalent among thinly traded and low-priced stocks.     

Effect of collateral characteristics on bank performance: Evidence from collateralized stocks in Taiwan

Taiwanese law requires directors of listed firms to disclose their stocks collateralized at banks creating the possibility of examining the characteristics of collateralized stocks and their influence on bank performance. This study demonstrates that the risk (value) attributes of collateralized stocks increase (reduce) bank efficiency yet reduce (increase) bank profits. Government-owned banks but not private banks require sufficiently high margins to prevent stock loans from non-performing. Furthermore, banks charge higher interest to cover the non-performing risk. Directors who lack funds, hold high turnover stocks, and/or have weak relationships with their banks prefer to collateralize their stocks at private banks.     

Risk Interpretation of the CAPM's Beta: Evidence from a New Research Method

This study tests the validity of using the CAPM beta as a risk control in cross‐sectional accounting and finance research. We recognize that high‐risk stocks should experience either very good or very bad returns more frequently compared to low‐risk stocks, that is, high‐risk stocks should cluster in the tails of the cross‐sectional return distribution. Building on this intuition, we test the risk interpretation of the CAPM's beta by examining if high‐beta stocks are more likely than low‐beta stocks to experience either very high or very low returns. Our empirical results indicate that beta is a strong predictor of large positive and large negative returns, which confirms that beta is a valid empirical risk measure and that researchers should use beta as a risk control in empirical tests. Further, we show that because the relation between beta and returns is U‐shaped, that is, high betas predict both very high and very low returns, linear cross‐sectional regression models, for example, Fama–MacBeth regressions, will fail on average to reject the null hypothesis that beta does not capture risk. This result explains why previous studies find no significant cross‐sectional relation between beta and returns.     

What impact does a change of fund manager have on mutual fund performance?

Using a unique database of UK fund manager changes over the period from 1997 to 2011, we examine the impact of such changes on fund performance. We find clear evidence to suggest that a manager change does affect the benchmark-adjusted performance of UK mutual funds. In particular we find a significant deterioration in the benchmark-adjusted returns of funds that were top performers before the manager exit and, conversely, a significant improvement in the average benchmark-adjusted returns of funds that were poor performers before the manager exit. Our use of the Carhart's (1997) four-factor model reveals that the improvement in average post manager exit performance is accompanied by a reduction in market risk, a slight reduction in exposure to small cap stocks, and an increase in exposure to value and momentum stocks. Overall, our results suggest that UK fund management companies have been relatively successful in replacing bad managers with better managers, but relatively unsuccessful at finding equivalent replacements for their top performing managers. We believe that regulators should therefore try to ensure that all efforts are made by fund management companies to inform all of their investors about a change in management.     

Asymmetric effects of federal funds target rate changes on S&P100 stock returns,volatilities and correlations

We study the effects of FOMC announcements of federal funds target rate decisions on individual stock returns, volatilities and correlations at the intraday level. For all three characteristics we find that the stock market responds differently to positive and negative target rate surprises. First, the average response to positive surprises (that is, bad news for stocks) is larger. Second, in case of bad news the mere occurrence of a surprise matters most, whereas for good news its magnitude is more important. These new insights are possible due to the use of high-frequency intraday data.     

The rising risks of fossil fuel lobbying

For 2009 to 2018, we find that fossil fuel firms are more likely to lobby and that lobbying expenditures are greater with increases in a firm's vulnerability to climate change news risk. The industry's resistance to a timely low-carbon transition has spawned a divestment movement that accelerated in 2014. Estimates of fossil fuel firm vulnerability to climate change news risk increase after 2013, strengthening firms' inclination to lobby just when this activity becomes less valued by shareholders. We consider the financial implications of continued climate policy obstruction for financial system stability and the success of the clean energy transition.     

A Tale of Two Anomalies: Higher Returns of Low‐Risk Stocks and Return Seasonality

Prior studies have shown that low beta and low volatility stocks earn higher average returns than high beta and high volatility stocks, contradicting the prediction of the capital asset pricing model and the fundamental relationship between risk and return. In this paper, we demonstrate that this phenomenon is driven by the seasonality of stock returns. We show that the risk‐return tradeoff does hold in the nonsummer months, and that switching to a portfolio of low‐risk stocks in summer outperforms—both in terms of absolute and in risk‐adjusted returns—buy and hold strategies as well as the Sell in May strategy of switching to treasury bills in summer.     

Why is timing perverse?

The existence of negative market timing, even for passive portfolios, poses a relevant puzzle when assessing portfolio management. In this paper, we develop a simple theoretical model so as to explain why such perverse market timing might occur and why those stocks with the lowest beta in upward markets exhibit pronounced negative timing. Our explanation is based on the existence of higher correlations of stocks in down markets than in up markets. We find that changes in beta, which drives timing, has four components; however, just two of these, mean covariance shift and covariances dispersion map, serve to explain the asymmetric behavior across stocks. We find that a high percentage of the negative market timing ability identified for mutual funds in the literature could be explained by this bias.     

Media Coverage and the Cross-section of Stock Returns

By reaching a broad population of investors, mass media can alleviate informational frictions and affect security pricing even if it does not supply genuine news. We investigate this hypothesis by studying the cross-sectional relation between media coverage and expected stock returns. We find that stocks with no media coverage earn higher returns than stocks with high media coverage even after controlling for well-known risk factors. These results are more pronounced among small stocks and stocks with high individual ownership, low analyst following, and high idiosyncratic volatility. Our findings suggest that the breadth of information dissemination affects stock returns.