High Idiosyncratic Volatility Research Articles

The Idiosyncratic Volatility Puzzle: A Time-Specific Anomaly

Given the availability of daily data over 1926-1962, it is surprising that there is no research examining the idiosyncratic volatility (IV) puzzle over this early period. This paper conducts an out-of-sample test on the IV phenomenon. We find that the negative relation between IV and expected returns only exists during the period 07/1963-12/1989, implying that the puzzle may be a result of data snooping bias. The result on time-special anomaly is robust for different sorting breakpoints and alternative measure of idiosyncratic volatility. Infrequent trading cannot account for the low average returns of stocks with high idiosyncratic volatility. With a striking contrast, the involving of short-term return reversals eliminates this dilemma.

Salience and Mutual Fund Investor Demand for Idiosyncratic Volatility

We find that mutual fund investors are more likely to both purchase and redeem funds with high idiosyncratic volatility (IV). Investors’ tendency to purchase high IV funds is largely driven by high IV funds having more extreme returns, which increases the salience of the fund. Including flexible controls for extreme past returns over multiple horizons decreases the effect of IV on new investment, and experimental evidence corroborates that increasing the salience of extreme returns increases investor demand for IV. Demand for IV is higher among retail investors and funds with otherwise lower salience. Collectively, the evidence suggests that extreme returns attract investor attention and contribute to investors’ risk seeking behavior when purchasing mutual funds. This paper was accepted by David Simchi-Levi, finance.

Predicting Equity Returns in Emerging Markets

ABSTRACT This study investigates the relation between firm-specific attributes and future equity returns in 23 emerging markets. Equal-weighted portfolio returns reveal strong evidence of short-term momentum (rather than reversal) and medium-term return momentum. We also find evidence that market beta, book-to-market ratio and downside risk metrics predict equity returns, however, these relations get weaker once value-weighting is used. In univariate regressions, smaller firms with higher idiosyncratic volatility, lottery-like characteristics and stock-specific downside risk are associated with higher future returns, however, these relations disappear in a multivariate setting. We conclude that the most robust cross-sectional effects are short- and medium-term return momentum.

The cross-section of industry equity returns and global tactical asset allocation across regions and industries

This study investigates which index characteristics predict returns in the cross-section of local industry indexes in six regions. The results show that geographical origin and market capitalization of indexes critically determine the predictive ability of characteristics. We find that industry indexes of any market capitalization with high earnings-to-price ratio yield higher expected returns in the US, Europe, and Asia-Pacific. Recent winner (loser) portfolios in Europe have a tendency to outperform (underperform) recent loser (winner) portfolios in the near future for all groups of market capitalization. Small portfolios with high idiosyncratic volatility in Asia-Pacific earn an idiosyncratic volatility premium. Dividend yield is positively related to future returns of small European portfolios. These results are robust to the inclusion of transaction costs and control variables and have implications for portfolio managers following a global tactical asset allocation policy.

It takes two to tango: Fundamental timing in stock market

AbstractIn this paper, we propose a fundamental timing strategy in both U.S. and Chinese stock markets to timing the fundamentals sorted portfolios such as value and profitability portfolios in the time‐series dimension. We find that fundamental timing strategies based on moving average (MA) timing signals could generate substantial performance gains relative to buy‐and‐hold strategies. The annualized average return of fundamental timing strategies reaches about 37% with Sharpe ratio nearly 1.30. These findings are robust to Fama–French factor model adjustment, alternative lag lengths of MA signals, holding days, and transaction costs. Moreover, the fundamental timing premium cannot be explained away by market timing or business cycle, and fundamental timing is more profitable among firms with high idiosyncratic volatility and high illiquidity.

Strategic Risk Shifting and the Idiosyncratic Volatility Puzzle: An Empirical Investigation

We find strong empirical support for the risk-shifting mechanism to account for the puzzling negative relation between idiosyncratic volatility and future stock returns. First, equity holders take on investments with high idiosyncratic risk when their firms are in distress and receive less monitoring from institutional holders as well as when the aggregate economy is in a bad state. Second, the strategically increased idiosyncratic volatility decreases equity betas, particularly in bad states when the market risk premium is high. The negative covariance between the equity beta and the market risk premium causes low and negative returns and alphas in firms with high idiosyncratic volatility. This paper was accepted by Tomasz Piskorski, finance.

Does what happen in Vegas stay in Vegas? Football gambling and stock market activity

We examine whether lagged football betting payoffs result in changes in retail investing in lottery-like stocks. We show that lagged, low betting imbalances are associated with increases in retail stock participation, particularly for lottery-like stocks. This finding implies support for the “break-even” hypothesis that following negative sentiment and losses from football gambling, investors use lottery-like stocks to offset losses or break-even. This result holds for lottery-like stocks defined based on high idiosyncratic volatility and skewness as well as stocks that trade in over-the-counter (OTC) markets. Finally, we address whether the reverse relation exists, finding that only OTC market activity leads to increases in football betting activity but not football betting imbalances. Overall, our paper contributes to the literature investigating the relation between gambling sentiment and stock market activity.

Preference for lottery features in real estate investment trusts

This paper provides strong and novel evidence of the preference among investors for lottery-like payoffs by documenting a strong intra-industry MAX effect in REITs. Specifically, REITs with high maximum daily returns (high MAX) over the past 1-month significantly underperform REITs with low maximum daily returns (low MAX) over the same period. Such underperformance is persistent in subsequent months, although the underperformance is significant only in several months. In general, high MAX REITs are smaller and exhibit lower prices and higher idiosyncratic volatility than other REITs. However, firm characteristics cannot explain the MAX effect among REITs. In contrast, the MAX effect could significantly explain the idiosyncratic volatility puzzle among REITs. Moreover, the MAX effect is more pronounced among REITs with low institutional ownerships, while investor sentiment has no significant effect on the MAX effect among REITs.

Volatility and the Cross-Section of Equity Returns: The Role of Short-Selling Constraints

IHS Markit data reveals that stocks with high idiosyncratic volatility are far more likely to be hard-to-borrow than low idiosyncratic volatility stocks. When hard-to-borrow stocks are excluded, the relation between idiosyncratic volatility (IVOL) and stock returns disappears. The relation between idiosyncratic volatility and returns is more accurately described as a relation between being hard-to-borrow and stock returns. Arbitrage risk, on the other hand, is far too small to explain mispricing of high IVOL stocks. When the idiosyncratic volatility of portfolios rather than individual stocks is considered, Sharpe ratios of mispriced IVOL portfolios are much greater than the value-weighted market’s Sharpe ratio.

The Value of Firm Networks: A Natural Experiment on Board Connections

This paper presents causal evidence of the effects of boardroom networks on firm value and compensation policies. We exploit exogenous variation in network centrality arising from a ban on interlocking directorates of Italian financial and insurance companies. We leverage this shock to show that firms whose centrality in the network rises after the reform experience positive abnormal returns around the announcement date and are better hedged against shocks. Information dissemination plays a central role: results are driven by firms that have higher idiosyncratic volatility, low analyst coverage, and more uncertainty surrounding their earnings forecasts. Firms benefit more from boardroom centrality when they are more central in the input-output network, hence more susceptible to upstream shocks, when they are less central in the cross-ownership network, or when they have low profitability or low growth opportunities. Network centrality also results in higher directors' compensation, due to rent sharing and improved executives' outside option, and more similar compensation policies between connected firms.

Changes in Market Uncertainty and Profitability of Idiosyncratic Volatility Anomaly in Korea

Purpose - The idiosyncratic volatility (IVOL) puzzle is the anomaly that lower IVOL stocks earn higher future returns. We examine if global market uncertainty and market fear affect idiosyncratic volatility anomaly profits in Korea. Design/methodology/approach - Change in market uncertainty and investor fear is measured by change in the volatility index (VIX). Stocks are sorted into quintile portfolios based on their IVOLs in each month. To measure the anomaly profit, the return spread between two extreme portfolios is computed. Risk-adjusted returns are also calculated relative to capital asset pricing model (CAPM) and the Fama and French model. Then, we compare the difference of the IVOL investing profits in the decreasing and increasing VIX periods. Findings - We find that in the months following a decrease in VIX, stocks with low IVOLs earn 2.5% higher profits than stocks with high IVOLs. However, no such anomaly arises in the months following an increase in the VIX. Research implications or Originality - This result implies that mispricing is more significant when investors’ fears regarding market uncertainty are abated. Also, investors can obtain the IVOL anomaly returns by buying low IVOL stocks when the VIX decreases and selling them the following month. This finding suggests that the Korean stock market is integrated with the global market.

Short-term momentum (almost) everywhere

Is there a short-term reversal effect outside the universe of individual stocks? To answer this, we investigate a comprehensive dataset of more than two centuries of returns on five major asset classes: equity indices, government bonds, treasury bills, commodities, and currencies. Contrary to stock-level evidence, we find a striking short-term momentum pattern: the most recent month’s return positively predicts future performance. The effect is not explained by established return predictors—including the standard momentum—and is robust to many considerations. The short-term momentum is strongest among assets of high idiosyncratic volatility and in periods of elevated return dispersion. Also, the strategy payoffs display partial commonality across different asset classes.

CEO Severance Pay and Corporate Tax Planning

ABSTRACTWe examine the association between CEO severance pay (i.e., payment a CEO would receive if s/he is involuntarily terminated) and corporate tax planning activities. We find that CEO severance pay is positively associated with corporate tax planning, consistent with CEO severance pay providing contractual protection against managers' career concerns and thereby inducing otherwise risk-averse managers to engage in incremental levels of tax planning. This result holds under an instrumental variable approach and propensity score matching, and survives alternative measures of CEO severance pay and corporate tax planning. Finally, we find that severance pay provides stronger tax planning incentives in situations where managers are expected to face greater career concerns—when they are less experienced, when they face stronger shareholder monitoring, and when they manage firms with higher idiosyncratic volatility. Overall, our results suggest that CEO severance pay represents a form of efficient contracting with otherwise risk-averse managers.

The Cross-Section of Volatility and Expected Returns: Then and Now

We successfully replicate the main results of Ang, Hodrick, Xing, and Zhang (2006): Aggregate-volatility risk and idiosyncratic volatility (IV) are each priced in the cross-section of stock returns from 1963 to 2000. We also examine the pricing of volatility outside the original time period and under more recent asset-pricing models. With the exception of NASDAQ stocks, aggregate-volatility risk continues to be priced in the years following the Ang et al. (2006) sample period, and none of the more recent asset-pricing models we consider consistently accounts for the pricing of aggregate-volatility risk. The difference in abnormal returns between stocks with high and low IV decreases but remains significant out-of-sample. More recent asset-pricing models do not resolve the IV anomaly for the Ang et al. (2006) sample, but the four-factor model of Stambaugh and Yuan (2017) and the six-factor model of Barillas and Shanken (2018) resolve the anomaly out-of-sample and over the extended period of 1967 to 2016. Finally, both models eliminate the arbitrage asymmetry that Stambaugh, Yu, and Yuan (2015) propose as an explanation of the IV anomaly.

Can tail risk explain size, book‐to‐market, momentum, and idiosyncratic volatility anomalies?

AbstractWe examine the impact of tail risk on the return dynamics of size, book‐to‐market ratio, momentum and idiosyncratic volatility sorted portfolios. Our time‐series analyses document significant portfolio return exposures to aggregate tail risk. In particular, portfolios that contain small, value, high idiosyncratic volatility and low momentum stocks exhibit negative and statistically significant tail risk betas. Our cross‐sectional analyses at the individual stock level suggest that tail risk helps in explaining the four pricing anomalies, particularly size and idiosyncratic volatility anomalies.

Do Credit Default Swap Prices Reveal the Presence of Informed Trading?

We attempt to answer a key question whether credit default swap (CDS) prices and price changes contain private information that are used by informed traders within 24 hours to cross-trade in the related equity market. By disaggregating daily stock return into day (exchange trading hours), evening, and night returns, we find that the credit default swap return of a stock, with high credit spread and high idiosyncratic volatility (hard-to-value), negatively impacts the next market-hours stock return in a significant way both via panel regression tests and via portfolio profitability tests. For stocks with low idiosyncratic volatility and thus higher predictability, the CDS return impact is milder and is opposite in direction, indicating a pattern of hedged investing. We show empirically that by evening after market-hours, the impacted stock return would reverse partially explanable by the well-established observation of trading overconfidence due to private information bias. For the case of low credit ratings stocks with high opaqueness or being hard-to-value, there is the additional interesting finding that large stock price changes due to CDS impact do not evidence any partial reversal on the eve of days in which actual credit rating downgrade happened. This reinforces the evidence of the presence of informed trading. We also find that limit-to-arbitrage such as stock illiquidity and short-sale constraint cannot fully explain the predictive results on stock returns based on CDS return signals.

Option trading after the opening bell and intraday stock return predictability

AbstractPrior literature finds that information is reflected in option markets before stock markets, but no study has explored whether option volume soon after market open has predictive power for intraday stock returns. Using novel intraday signed option‐to‐stock volume data, we find that a composite option trading score (OTS) in the first 30 min of market open predicts stock returns during the rest of the trading day. Such return predictability is greater for smaller stocks, stocks with higher idiosyncratic volatility, and stocks with higher bid–ask spreads relative to their options’ bid–ask spreads. Moreover, OTS is a significantly stronger predictor of intraday stock returns after overnight earnings announcements. The evidence suggests that option trading in the 30 min after the opening bell has predictive power for intraday stock returns.

Idiosyncratic volatility and the cross-section of anomaly returns: is risk your Ally?

ABSTRACTDue to arbitrage risk asymmetries, the relationship between idiosyncratic risk and expected returns is positive (negative) among overpriced (underpriced) stocks. We offer a new active anomaly-selection strategy that capitalizes on this effect. To this end, we consider 11 equity anomalies in the U.S. market for years 1963–2016. Buying (selling) long (short) legs of the anomaly portfolios with the highest idiosyncratic volatility produces monthly abnormal returns ranging from 0.97% to 1.14% per month, outperforming a naive benchmark that equally weights all the anomalies by 45–70%. The effect cannot be subsumed by any other established anomaly-return predictor, such as momentum or seasonality. The results are robust to many considerations, including different numbers of anomalies in the portfolios, subperiod analysis, as well as estimation of idiosyncratic risk from the alternative models and throughout different periods.

Firm Life Cycle, Expectation Errors and Future Stock Returns

I study the return predictability of firm life cycle, originally documented by Dickinson (2011). I show that a hedge portfolio strategy going long on mature firms and short on introduction firms generates a significant hedge portfolio return of 1.4% per month in return-weighted portfolios and 0.75% in value-weighted portfolios. The returns to firm life cycle are related to investors’ and analysts’ expectation errors, are driven by market-wide investor sentiment, and are more pronounced among stocks with low institutional ownership and high idiosyncratic volatility. Quantile regressions show that introduction firms have considerably greater uncertainty and skewness in future earnings growth outcomes than mature firms, such that analysts are better able to justify optimistically biased forecasts for introduction firms compared to mature firms.

Short-Term Momentum (Almost) Everywhere

Is there a short-term reversal effect outside the universe of individual stocks? To answer this, we investigate a comprehensive dataset of more than two centuries of returns on five major asset classes: equity indices, government bonds, treasury bills, commodities, and currencies. Contrary to stock-level evidence, we find a striking short-term momentum pattern: the most recent month’s return positively predicts future performance. The effect is not explained by established return predictors — including the standard momentum — and is robust to many considerations. The short-term momentum is strongest among assets of high idiosyncratic volatility and in periods of elevated return dispersion. Also, the strategy payoffs display partial commonality across different asset classes.