Volatility Effects

Correlations among asset returns vary over time, introducing risk to the benefits of diversification. Intervals of extraordinarily high correlation amplify marketwide volatility and are disruptive to asset allocation policies. Does the risk of such correlation shocks explain the volatility risk premium associated with marketwide (equity index) options? In the July 2008 version of their paper entitled “The Price of Correlation Risk: Evidence from Equity Options”, Joost Driessen, Pascal Maenhout and Grigory Vilkov examine how correlation shocks affect the returns of options for a broad stock index and of options for its individual component stocks. Using daily returns for the S&P 100 index, its components and associated options over the period 1996-2003, they conclude that: Keep Reading

Why does the volatility of the stock market as implied by the prices of equity index options generally exceed actual (realized) volatility, thereby indicating large returns for sellers of index options? Is the reward of selling such options commensurate with the risk? In the June 2008 version of his paper entitled “The Volatility Premium”, Bjorn Eraker models the volatility risk premium based on the long-run effects of small (normal diffusion) and large (non-normal jumps) shocks to volatility. Using daily returns for the S&P 500 index and daily levels of the CBOE Volatility Index (VIX) over the period 1990-2007, he concludes that: Keep Reading

Does the volatility risk premium, the difference between options-implied volatility and future realized (actual) volatility, vary systematically with the four most widely used equity risk factors (market, size, book-to-market and momentum)? In other words, might the four factors point to pockets of underpriced or overpriced options? In their November 2008 paper entitled “Implied and Realized Volatility in the Cross-Section of Equity Options”, Manuel Ammann, David Skovmand and Michael Verhofen investigate the factor dependence of the volatility premium for U.S. equities. Using a sample of all U.S. equity at-the-money call options 91 days from expiration over the period January 1996 through April 2006, along with associated stock price and firm fundamentals data, they conclude that: Keep Reading

Are stock pickers more likely to out-pick the market by focusing on stocks that resist market efficiency? In their December 2008 paper entitled “When is Stock-Picking Likely to be Successful? Evidence from Mutual Funds”, Ying Duan, Gang Hu and David McLean examine changes in quarterly holdings of mutual funds to measure how the stock-picking performance of fund managers varies with stock idiosyncratic volatility (volatility that indicates risk factors different from those of the overall stock market). Using quarterly mutual fund stock holdings data and monthly stock return data for the period 1980-2003, they conclude that: Keep Reading

Standard deviation is likely the most widely used measure of investment risk, but quadratic dispersion from the mean not be the most intuitive measure. There is evidence that investors confuse standard deviation with mean absolute deviation, and they may further misinterpret standard deviation due to its “normal” association with the Gaussian distribution (inapplicable for some financial data series). Would some other baggage-free measure of risk make more sense to investors? In his November 2008 paper entitled “The Gain-Loss Spread: A New and Intuitive Measure of Risk”, Javier Estrada proposes the gain-loss spread (GLS) as an intuitive and useful measure of investment risk. GLS is the difference between the expected gain (probability of gain times average gain) and the expected loss (probability of loss times average loss). Using monthly return data for 49 country indexes (22 developed and 27 emerging) and 57 industry indexes from initial availability through December 2007, he concludes that: Keep Reading

The Chicago Board Options Exchange (CBOE) Volatility Index (VIX) gets special attention from investing experts and the financial media as the “investor fear gauge.” What are the origins of VIX, and why was it created? In his November 2008 draft paper entitled Understanding VIX, VIX creator Robert Whaley describes the purpose, history and essential characteristics of this index. Using historical data from January 1986 through October 2008, he explains that: Keep Reading

A rare sighting… Keep Reading

Are investors/traders irrationally attracted to stocks that have recently acted like winning lottery tickets? In their August 2008 paper entitled “Maxing Out: Stocks as Lotteries and the Cross-Section of Expected Returns”, Turan Bali, Nusret Cakici and Robert Whitelaw investigate the significance of extreme positive past daily returns for future returns. Specifically, they examine next-month returns for stocks sorted by maximum daily return during the past month. Using daily and monthly returns, and contemporaneous firm characteristics, for a broad sample of stocks over the period July 1962 thorough December 2005, they conclude that: Keep Reading

Does the degree to which out-of-the-money (OTM) put options are “overpriced” imply future returns for associated stocks? In other words, are options traders especially well-informed? In their March 2008 paper entitled “What Does Individual Option Volatility Smirk Tell Us about Future Equity Returns?”, Xiaoyan Zhang, Rui Zhao and Yuhang Xing test whether option prices for individual stocks contain important information for the underlying equities. They focus on the predictive power of volatility smirks, the difference between the implied volatilities of OTM put options and at-the-money (ATM) call options. Using daily option and underlying stock price data for all firms with listed options during 1996-2005, they conclude that: Keep Reading

Do traders with solid information about firm prospects use equity options to get leverage and avoid short selling constraints? Two recent papers address this question by testing the predictive power of distortions in out-of-the money option prices for individual stocks. In their December 2007 paper entitled “Deviations from Put-Call Parity and Stock Return Predictability”, Martijn Cremers and David Weinbaum examine the power of relatively expensive options to predict returns for individual stocks. In a similar March 2008 paper entitled “What Does Individual Option Volatility Smirk Tell Us about Future Equity Returns?”, Xiaoyan Zhang, Rui Zhao and Yuhang Xing focus on relatively expensive put options as indicators of bad news and poor future returns for individual stocks. Using options pricing and associated stock return data over the period 1996-2005, these two studies conclude that: Keep Reading