Is stochastic volatility relevant for dynamic portfolio choice under ambiguity?

Literature on dynamic portfolio choice has been finding that volatility risk has low impact on portfolio choice. For example, using long-run US data, Chacko and Viceira [2005. “Dynamic Consumption and Portfolio Choice with Stochastic Volatility in Incomplete Markets.” The Review of Financial Studies 18 (4): 1369–1402] found that intertemporal hedging demand (required by investors for protection against adverse changes in volatility) is empirically small even for highly risk-averse investors. We want to assess if this continues to be true in the presence of ambiguity. Adopting robust control and perturbation theory techniques, we study the problem of a long-horizon investor with recursive preferences that faces ambiguity about the stochastic processes that generate the investment opportunity set. We find that ambiguity impacts portfolio choice, with the relevant channel being the return process. Ambiguity about the volatility process is only relevant if, through a specific correlation structure, it also induces ambiguity about the return process. Using the same long-run US data, we find that ambiguity about the return process may be empirically relevant, much more than ambiguity about the volatility process. Anyway, intertemporal hedging demand is still very low: investors are essentially focused on the short-term risk–return characteristics of the risky asset.     

Portfolio selection: An extreme value approach

We show theoretically that lower tail dependence (χ), a measure of the probability that a portfolio will suffer large losses given that the market does, contains important information for risk-averse investors. We then estimate χ for a sample of DJIA stocks and show that it differs systematically from other risk measures including variance, semi-variance, skewness, kurtosis, beta, and coskewness. In out-of-sample tests, portfolios constructed to have low values of χ outperform the market index, the mean return of the stocks in our sample, and portfolios with high values of χ. Our results indicate that χ is conceptually important for risk-averse investors, differs substantially from other risk measures, and provides useful information for portfolio selection.     

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.     

Fund Manager Use of Public Information: New Evidence on Managerial Skills

We show theoretically that the responsiveness of a fund manager's portfolio allocations to changes in public information decreases in the manager's skill. We go on to estimate this sensitivity (RPI) as the R² of the regression of changes in a manager's portfolio holdings on changes in public information using a panel of U.S. equity funds. Consistent with RPI containing information related to managerial skills, we find a strong inverse relationship between RPI and various existing measures of performance, and between RPI and fund flows. We also document that both fund‐ and manager‐specific attributes affect RPI.     

Information Inertia

We show that aversion to risk and ambiguity leads to information inertia when investors process public news about assets. Optimal portfolios do not always depend on news that is worse than expected; hence, the equilibrium stock price does not reflect this bad news. This informational inefficiency is more severe when there is more risk and ambiguity but disappears when investors are risk‐neutral or the news is about idiosyncratic risk. Information inertia leads to news momentum (e.g., after earnings announcements) and is consistent with low household trading activity. An ambiguity premium helps explain the macro and earnings announcement premium.     

Home-field advantage or a matter of ambiguity aversion? Local bias among German individual investors

This paper investigates whether familiarity induced by ambiguity aversion can help explaining the local bias phenomenon among individual investors. Using geographic closeness as a proxy for investor familiarity, we find that investors pull out of (unfamiliar) remote stocks and pour into (familiar) local stocks during times of increased market uncertainty. Moreover, the magnitude of this ‘flight to familiarity’ increases in the spread of an investor's ambiguity (about expected returns) between local and remote stocks. Our results prove robust to a number of alternative explanations of local bias. Specifically, we rule out a ‘home-field advantage’, where investors are able to translate information advantages about nearby companies into excess returns on their local stockholdings. We conclude that individual investors’ local bias is induced by ambiguity aversion in the portfolio selection process rather than a trading strategy based on superior information about local companies.     

When it comes to the crunch: Retail investor decision-making during periods of market volatility

Attitude to risk questionnaires are widely used by financial advisors to recommend investments of appropriate risk levels to their clients. Yet the usefulness of this instrument to gauge how investors will react when faced with extreme volatility in the values of their assets remains untested. Using realistic scenarios and based on a large-scale survey in the UK, in this study we examine how the investing public reacts to actual portfolio losses. We find that conventional risk tolerance measures are inadequate for determining whether investors would ‘sell out’ or hold their portfolios in such circumstances. On the other hand, we find that past experience, emotions and personality characteristics, including measures of financial self-efficacy and extraversion, are significant predictors of investor reactions to market crashes.     

The Diversification Effects of Initial Public Offerings

Abstract:  A firm's stock becomes publicly tradable through an initial public offering (IPO). This study suggests a portfolio diversification perspective to explore IPOs. We examine whether investors can gain diversification benefits by adding an IPO portfolio to a set of benchmark portfolios sorted by firm size and book-to-market ratio. Using US IPOs from 1980-2002, we find that adding a value-weighted IPO portfolio does lead to a statistically and economically significant enlargement of the investment opportunity set for investors relative to investing solely in a set of benchmark portfolios. Specifically, the Sharpe ratio of the tangency portfolio increases by 5.50% on average after including IPO stocks. Furthermore, IPOs associated with prestigious lead underwriters are the main source of this augmentation of the mean-variance investment opportunity set. Finally, our study implies that issuing IPO exchange traded funds or similar products can provide diversification gains to investors.     

Access to information and international portfolio allocation

We examine whether foreign equity holdings of portfolio investors depend on the level of information accessibility between the investors’ home and host countries. Using a comprehensive data set, alternative measures of information accessibility and robust analytical techniques, we show that differences in access to cross-country information significantly influence investors’ portfolio allocation decisions. Furthermore, the results suggest that for a given level of access to information, investors prefer to invest more in countries with a higher quality of legal/macro-institutions. Finally, the findings also confirm that the implications of information accessibility are more pronounced when markets are turbulent.     

Risk-taking begets risk-taking: Evidence from casino openings and investor portfolios

We provide evidence that casino openings can have spillover effects on an individual's portfolio risk-taking. Using investor-level brokerage data and the initial legalization and opening of commercial casinos in the United States as a quasi-natural experiment, we find that, after a casino opens in close geographical proximity to investors, those with a high propensity to gamble (PTG) increase their idiosyncratic portfolio risk by 12.88% relative to those unlikely to gamble. This effect lasts for approximately 3 months and does not affect systematic portfolio risk. These results suggest that increased access to gambling can temporarily increase portfolio risk-taking for those with a PTG.     

Information and the Cost of Capital

We investigate the role of information in affecting a firm's cost of capital. We show that differences in the composition of information between public and private information affect the cost of capital, with investors demanding a higher return to hold stocks with greater private information. This higher return arises because informed investors are better able to shift their portfolio to incorporate new information, and uninformed investors are thus disadvantaged. In equilibrium, the quantity and quality of information affect asset prices. We show firms can influence their cost of capital by choosing features like accounting treatments, analyst coverage, and market microstructure.     

Difference of opinion among investors versus analysts

We construct an investor-based measure of differences of opinion (DO) to investigate the different implications of DO between retail investors (DOR), institutional investors (DOI), and analysts (DOA) on asset pricing. Using Chinese stock data, we find that three DO measures (DOR, DOI, and DOI) are negatively related to future returns; DOI’s ability to predict returns can be partly explained by DOR and DOA, whereas DOR contains incremental information not available from DOI and DOA. DOR is more strongly associated with the severe overvaluation caused by retail investors’ optimism than DOI or DOA, emphasising the specific role of retail investors in China’s market. We further show that DOI and DOA are the results of the differences in their information sets, whereas DOR are the results of different interpretations of public information.     

Innovations in financing: The impact of anchor investors in Indian IPOs

In 2009, the Securities Exchange Board of India allowed qualified institutional investors to anchor initial public offerings (IPOs) by participating in the issue at a price and allocation publicly disclosed preceding the issue. We study anchor investors (AIs) in Indian IPOs during 2009–2017. We find the share allotment and the number of AIs separately have significant impacts on valuation and underpricing; however, the net effect is nonsignificant. Further, AIs significantly influence other institutional investors' participation in the IPO and induce lower aftermarket volatility. Overall, our evidence suggests that AIs boost demand for and mitigate ex ante information uncertainty of IPOs.     

Is there useful information in the ‘use of proceeds’ disclosures in IPO prospectuses?

This study contributes evidence on the valuation relevance of the ‘use of proceeds’ disclosure in the initial public offering (IPO) prospectus. This article develops a classification of ‘use of proceeds’ disclosures that aims to capture information embedded in the disclosures relating to the purpose (growth, production, financing) and amount committed to specific assets. These measures are then related to IPO underpricing, survival prediction and expected and realised prospects of the IPOs. The results suggest the ‘use of proceeds’ disclosure categories have incremental information over other sources of information for underpricing, for predicting firm survival and in the case of some disclosure categories, for investors’ evaluation of the firms’ prospects and risks in the early years after listing.     

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.     

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.     

Information immobility,industry concentration,and institutional investors’ performance

This paper examines foreign institutional investors’ portfolio allocation and performance in US securities. We test how information immobility, proxied by information barriers between the investors’ home markets and the US, influences portfolio strategies. Consistent with theoretical predictions, foreign institutional investors’ total investment in the US is negatively related to information immobility. Similarly, information immobility is a significant driver of portfolio under-diversification across industries. Industry concentration has declined over time, consistent with declining search costs. Industry-concentrated portfolios outperform more diversified portfolios for both foreign and US institutional investors. Concentration especially helps institutional investors with the easiest access to information.     

Model Misspecification and Underdiversification

In this paper, we study intertemporal portfolio choice when an investor accounts explicitly for model misspecification. We develop a framework that allows for ambiguity about not just the joint distribution of returns for all stocks in the portfolio, but also for different levels of ambiguity for the marginal distribution of returns for any subset of these stocks. We find that when the overall ambiguity about the joint distribution of returns is high, then small differences in ambiguity for the marginal return distribution will result in a portfolio that is significantly underdiversified relative to the standard mean‐variance portfolio.     

Benefits of diversifying investments into emerging markets with time-varying correlations: An Australian perspective

Australian investors can reduce their overall portfolio risk by diversifying into equities from other markets. Emerging markets have attracted significant interest because of their low correlations with Australian equity market returns; however, a number of studies have indicated that correlations between equity returns are increasing over time, so using unconditional estimates of correlations in a portfolio optimization model can result in the selection of a portfolio that may not be optimal.We use an Asymmetric Dynamic Conditional Correlation GARCH model to estimate time-varying correlations and include these correlation estimates in the portfolio optimization model. The assets used for portfolio construction comprise seven emerging market indices that are available to foreign investors. This study finds that, despite increasing correlations, there are still potential benefits for Australian investors who diversify into international emerging markets.     

Financial literacy and portfolio diversification

We use a survey of individual investors disclosed by the Portuguese Securities Commission (CMVM) in May 2005 to study the impact of investors’ levels of financial literacy on portfolio diversification. We consider distinct aspects of financial literacy, and control for socioeconomic and behavioral differences among individual groups of investors. Our results suggest that investors’ educational levels and their financial knowledge have a positive impact on investor diversification. The information sources used by retail investors to gather information on markets and financial products also have a significant impact on the number of different assets included in a portfolio.