research on this hypothesis to open-market share repurchases. Empirical tests showed that the implied volatility spread was not … implied volatility spread and subsequent stock return volatility around open-market share repurchase events. We concluded that … option traders have private information on the volatility of stock returns and superior information processing ability that …

reflect information-driven and noise-induced volatilities. We find that all volatility components reveal distinct dynamics and … significantly declines thereafter. Moreover, news-affected responses in all volatility components are influenced by order flow … imbalances. -- Efficient Return ; Macroeconomic Announcements ; Microstructure Noise ; Informational Volatility …