摘要：This paper examines data from 45 world markets and shows that the previously documented relation between mean returns and idiosyncratic volatility arises because of biases in volatility estimates that we can attribute to the bid–ask bounce in trade prices. We show that no significant relation exists between mean returns and idiosyncratic volatility estimated from quote-midpoint returns. Further, there is no significant relation between mean returns and the portion of transaction-price-based idiosyncratic volatility that is orthogonal to bid–ask spreads. The pricing of idiosyncratic volatility is due to the negative pricing of the bid–ask spread.

　　本文刊登于Journal of Financial and Quantitative Analysis ，2015年，50卷，第6期，1269–1292页。Journal of Financial and Quantitative Analysis为永利官网金融A类期刊，胡婷为yL23411永利官网登录金融系副教授。