This factor is designed to capture the extent to which a company's quarterly revenue exceeds market expectations and is normalized using the volatility of revenue surprises over the past eight quarters. A positive value indicates that the company's revenue performance exceeds expectations, which may trigger a positive reaction in market sentiment and push up stock prices; a negative value indicates that the company's revenue performance is lower than expected, which may trigger a negative reaction in market sentiment and depress stock prices. This factor exploits the post-earnings announcement price drift effect, which indicates that after the earnings announcement is released, the stock price will continue to drift in the direction implied by the announcement information for a period of time. This factor takes into account the historical volatility of revenue surprises, thereby making a fairer comparison of revenue surprises across different companies or at different points in time. A larger standardized revenue surprise may indicate a stronger stock price reaction than a smaller standardized revenue surprise.