Individual investors’ information use,subjective expectations,and portfolio risk and return

What information do individual investors use when making their financial decisions and how is it related to their stock market expectations, their confidence in these expectations, and the risk and return of their stock portfolios? I study these questions by combining survey data on the information usage among individual investors in Sweden with detailed registry data on their stock portfolios. I find that investors use filtered financial information (e.g. information packaged by a professional intermediary) more frequently than they use unfiltered financial information (e.g. information from annual reports and financial statements). Investors who frequently use filtered financial information are, however, more confident in their stock market expectations and take larger risks in their stock portfolios. Investors that instead use unfiltered financial information take lower portfolio risks and obtain higher portfolio returns. The findings in this paper thus suggest that investors can improve their financial decisions by using more unfiltered financial information rather than filtered financial information when they make their financial decisions.     

Insiders' hedging in a jump diffusion model

In this paper, we formulate the optimal hedging problem when the underlying stock price has jumps, especially for insiders who have more information than the general public. The jumps in the underlying price process depend on another diffusion process, which models a sequence of firm-specific information. This diffusion process is observed only by insiders. Nevertheless, the market is incomplete to insiders as well as to the general public. We use the local risk minimization method to find an optimal hedging strategy for insiders. We also numerically compare the value of the insider's hedging portfolio with the value of an honest trader's hedging portfolio for a simulated sample path of a stock price.     

Ambiguous Information,Portfolio Inertia,and Excess Volatility

I study the effects of risk and ambiguity (Knightian uncertainty) on optimal portfolios and equilibrium asset prices when investors receive information that is difficult to link to fundamentals. I show that the desire of investors to hedge ambiguity leads to portfolio inertia and excess volatility. Specifically, when news is surprising, investors may not react to price changes even if there are no transaction costs or other market frictions. Moreover, I show that small shocks to cash flow news, asset betas, or market risk premia may lead to drastic changes in the stock price and hence to excess volatility.     

Optimal Portfolio Choice for Long-Horizon Investors with Nontradable Labor Income

This paper examines how risky labor income and retirement affect optimal portfolio choice. With idiosyncratic labor income risk, the optimal allocation to stocks is unambiguously larger for employed investors than for retired investors, consistent with the typical recommendations of investment advisors. Increasing idiosyncratic labor income risk raises investors' willingness to save and reduces their stock portfolio allocation towards the level of retired investors. Positive correlation between labor income and stock returns has a further negative effect and can actually reduce stockholdings below the level of retired investors.     

HEDGING FIXED-RATE PREFERRED STOCK INVESTMENTS

Corporations seeking to maximize the return on their cash reserve resources have an incentive to invest in traditional preferred stock because of their right to exclude 70% of the dividends from taxation. Nevertheless, fixed-rate preferred stock investments may contribute significantly to the return volatility of a cash portfolio and cause unacceptable losses to the corporate investors. As a result, many corporations might consider such higher-return investments only if they can hedge away a sufficient amount of risk. The research presented in this article seeks to evaluate how much of the return variation of fixed-rate preferred equity portfolios can be reduced with various hedging strategies.
This research shows that it is possible to reduce the risk of preferred stock investments significantly through the use of hedges employing some combination of fixed income futures and/or options. Although some risk remains even with the hedged preferred stock portfolio, the author demonstrates that money market assets can be combined with a hedged preferred stock portfolio to create a position that has no material chance of loss but expected after-tax returns higher than those on money market investments. In addition, the article also shows the high level of profitability associated with a strategy of increasing the size of liquid reserves in order to allow for losses related to an unhedged preferred stock component of those reserves.     

基于VaR的开放式股票型基金市场风险的测量与评价

通过采用半参数法计算投资组合VaR,得到相应VaR的近似置信区间,并结合成分VaR、边际VaR对投资组合vaR进行分解,结果发现,VaR作为风险管理工具同样可以有效应用于开放式股票型基金市场风险的测量与评价.     

In Defense of Technical Analysis

Many investors occasionally receive what they believe to be nonpublic information about a security. Others feel that by applying superior analytical skills to public information, they are able to arrive at valuable insights that are not generally appreciated. In either case, there is a substantial opportunity for profit if the investor is correct. The investor must be correct on two counts. First, the estimate of the worth of the information must be reasonably accurate in terms of its impact on the price of the stock, and second, the investor must make a realistic assessment of the likelihood that the market already has received the information or insight in question. This paper is concerned only with the latter problem. The probability distribution of the date on which the market receives information already in the hands of the investor is calculated for a simple model of information propagation. It is then shown how this probability distribution can be brought to bear on the management of a portfolio.     

信息不对称、过度自信与股价变动

信息传导的非同步和投资者情绪变化是股票市场的两个典型特征,前者会引发投资者之间出现信息不对称问题,后者主要体现为投资者过度自信,两者共同作用影响股票价格变动。本文将信息不对称和投资者过度自信情绪置于同一个分析框架,建立两阶段动态序贯定价理论模型研究现实市场上信息传导过程中股价变动的内在机制。结果表明:(1)面临新信息的进入,投资者对股票收益预期的调整与均衡价格之间具有正相关关系;(2)面临有利消息时,过度自信投资者比例越大,股票的均衡价格越高,投资收益将越低;面临不利消息时则相反;(3)随着过度自信投资者比例以及过度自信程度升高,市场风险溢价将下降;(4)投资者群体在信息传导过程中出现分化,对股价变动形成异质信念,未获取信息和获取信息但未出现过度自信的投资者认为股价被高估,获取信息且出现过度自信的投资者认为价格被低估,促使更多的交易,引发市场成交量和股价变动;(5)过度自信投资者比例与过度自信程度提高均会对市场效率产生正向影响,而对市场深度具有负向效应。最后,基于理论结果对非对称性和持续性等典型的市场波动性特征进行解释。     

Index portfolio and welfare analysis under heterogeneous beliefs

With a growing popularity of index funds, we adopt a differences-in-opinion, general equilibrium framework to examine theoretically whether investors are better off with an index portfolio than active investing. In contrary to the conventional view, we find that, even for an active investor with the most accurate belief, switching to an index portfolio can significantly improve his expected ex-post welfare when the active investors have incorrect beliefs or face incomplete information. Moreover, the welfare improvement becomes more substantial when the active investors are more risk averse.     

Equilibrium Portfolio Strategies in the Presence of Sentiment Risk and Excess Volatility

Our objective is to identify the trading strategy that would allow an investor to take advantage of "excessive" stock price volatility and "sentiment" fluctuations. We construct a general equilibrium "difference-of-opinion" model of sentiment in which there are two classes of agents, one of which is overconfident about a public signal, while still optimizing intertemporally. Overconfident investors overreact to the signal and introduce an additional risk factor causing stock prices to be excessively volatile. Consequently, rational investors choose a conservative portfolio; moreover, this portfolio depends not just on the current price divergence but also on their prediction about future sentiment and the speed of price convergence.     

资金占用、股价暴跌风险对信息透明度的影响研究

以1999-2014年中国 A 股主板上市公司为研究样本,考量资金占用、股价暴跌风险对信息透明度影响。结果表明：大股东的资金占用程度越高,越容易给公司股价带来暴跌风险;股价发生暴跌后管理层采取相应策略改善形象,提高公司信息透明度。鉴此,投资者应利用大股东资金占用、股价暴跌与信息透明度之间的逻辑关系,构建投资套利组合;同时监管者需加强对大股东资金占用和信息透明度的监管,保护中小投资者利益。     

Investment strategies in the long run with proportional transaction costs and a HARA utility function

We consider an agent who invests in a stock and a money market in order to maximize the asymptotic behaviour of expected utility of the portfolio market price in the presence of proportional transaction costs. The assumption that the portfolio market price is a geometric Brownian motion and the restriction to a utility function with hyperbolic absolute risk aversion (HARA) enable us to evaluate interval investment strategies. It is shown that the optimal interval strategy is also optimal among a wide family of strategies and that it is optimal also in a time changed model in the case of logarithmic utility.     

Portfolio selection and skewness: Evidence from international stock markets

This paper finds that the returns of the world's 14 major stock markets are not normally distributed, and that the correlation matrix of these stock markets was stable during the January 1988–December 1993 time period. Polynomial goal programming, in which investor preferences for skewness can be incorporated, is utilized to determine the optimal portfolio consisting of the choices of 14 international stock indexes. The empirical findings suggest that the incorporation of skewness into an investor's portfolio decision causes a major change in the construction of the optimal portfolio. The evidence also indicate that investors trade expected return of the portfolio for skewness.     

股吧评论、分析师跟踪与股价崩溃风险——关于模糊信息的信息含量分析

东方财富股吧等股票论坛日渐活跃,反映了投资者对获得上市公司真实、完整、及时信息的强烈需求。尽管股吧有助于促进信息传播,但仍是非正式的信息发布平台,股吧评论本质上是一种模糊信息。为探明股吧评论的信息含量,本文以2012—2017年A股上市公司为研究样本,研究股吧评论对股价崩溃风险的影响,以及同样属于模糊信息的分析师跟踪在这一过程中可能产生的作用。实证结果表明,股吧评论分歧越小,股价崩溃风险越大,并且分析师跟踪人数和研报数量在上述影响过程中发挥中介作用。研究结果有助于厘清股吧评论影响股价崩溃风险的路径和机理,既丰富了股价崩溃风险成因的研究,也揭示了股吧评论、分析师跟踪等模糊信息的信息含量。     

Why inexperienced investors do not learn: They do not know their past portfolio performance

Recently, researchers have gone a step further from just documenting biases of individual investors. More and more studies analyze how experience affects decisions and whether biases are eliminated by trading experience and learning. A necessary condition to learn is that investors actually know what happened in the past and that the views of the past are not biased. We contribute to the above mentioned literature by showing why learning and experience go hand in hand. Inexperienced investors are not able to give a reasonable self-assessment of their own past realized stock portfolio performance which impedes investors' learning ability. Based on the answers of 215 online broker investors to an Internet questionnaire, we analyze whether investors are able to correctly estimate their own realized stock portfolio performance. We show that investors are hardly able to give a correct estimate of their own past realized stock portfolio performance and that experienced investors are better able to do so. In general, we can conclude that we find evidence that investor experience lessens the simple mathematical error of estimating portfolio returns, but seems not to influence their “behavioral” mistakes pertaining to how good (in absolute sense or relative to other investors) they are.     

Portfolio choice and equilibrium in capital markets with safety-first investors

This paper develops optimal portfolio choice and market equilibrium when investors behave according to a generalized lexicographic safety-first rule. We show that the mutual fund separation property holds for the optimal portfolio choice of a risk-averse safety-first investor. We also derive an explicit valuation formula for the equilibrium value of assets. The valuation formula reduces to the well-known two-parameter capital asset pricing model (CAPM) when investors approximate the tail of the portfolio distribution using Tchebychev's inequality or when the assets have normal or stable Paretian distributions. This shows the robustness of the CAPM to safety-first investors under traditional distributional assumptions. In addition, we indicate how additional information about the portfolio distribution can be incorporated to the safety-first valuation formula to obtain alternative empirically testable models.     

名义价格幻觉——基于证券分析师目标价格预测的经验证据

本文利用证券分析师发布的股票目标价格预测,为名义价格幻觉提供了能够直接反映心理预期的经验证据。研究发现,证券分析师对低价股未来收益的心理预期显著高于高价股,该行为偏误在规模小、上市时间短、股票波动性大、财务透明度低和无形资产占比高等估值难度更大的股票中表现得更加明显。我们还利用股票送转,对证券分析师是否受到名义价格幻觉的影响做进一步验证,发现由送转引起的与基本面无关的名义价格下降显著提升了证券分析师对股票未来回报的心理预期。进一步研究表明,上述发现并不是因为证券分析师准确预见了低价股和高价股未来有不同的投资机会,也不是为了最大化其供职证券公司的利益而有意迎合投资者。     

Portfolio risk management in a data-rich environment

We study risk assessment using an optimal portfolio in which the weights are functions of latent factors and firm-specific characteristics (hereafter, diffusion index portfolio). The factors are used to summarize the information contained in a large set of economic data and thus reflect the state of the economy. First, we evaluate the performance of the diffusion index portfolio and compare it to both that of a portfolio in which the weights depend only on firm-specific characteristics and an equally weighted portfolio. We then use value-at-risk, expected shortfall, and downside probability to investigate whether the weights-modeling approach, which is based on factor analysis, helps reduce market risk. Our empirical results clearly indicate that using economic factors together with firm-specific characteristics helps protect investors against market?risk.     

Which past returns affect trading volume?

Anecdotal evidence suggests and recent theoretical models argue that past stock returns affect subsequent stock trading volume. We study 3,000 individual investors over a 51 month period to test this apparent link between past returns and volume using several different panel regression models (linear panel regressions, negative binomial panel regressions, Tobit panel regressions). We find that both past market returns as well as past portfolio returns affect trading activity of individual investors (as measured by stock portfolio turnover, the number of stock transactions, and the propensity to trade stocks in a given month). After high portfolio returns, investors buy high risk stocks and reduce the number of stocks in their portfolio. High past market returns do not lead to higher risk taking or underdiversification. We argue that the only explanations for our findings are overconfidence theories based on biased self-attribution and differences of opinion explanations for high levels of trading activity.