When Stock Idiosyncratic Volatility Works
April 18, 2012 - Volatility Effects
For which stocks does market-adjusted (idiosyncratic) volatility work as an indicator of future returns (see “No Reward for Risk?”)? In their January 2012 paper entitled “Dissecting the Idiosyncratic Volatility Anomaly”, Linda Chen, George Jiang, Danielle Xu and Tong Yao measure the idiosyncratic volatility premium in different subsamples of U.S. stocks. To measure the premium, they focus on differences in average monthly returns and four-factor (market, size, book-to-market, momentum) alphas between both value-weighted and equal-weighted top and bottom deciles of prior-month idiosyncratic volatility. They consider the following stock universe subsamples: (1) common stocks and non-common stocks; (2) microcap, small and big stocks (breakpoints at the 20th and 50th percentiles of NYSE stock capitalizations); (3) stocks priced above $10, between $5 and $10 and below $5; and, (4) January and non-January returns. Using daily returns for NYSE/AMEX/NASDAQ common and non-common stocks, and for a value-weighted market index, to calculate monthly idiosyncratic volatility during 1963 through 2010, they find that: Keep Reading