Security Price Reactions to Initial Reviews of Common Stock by the Value Line Investment Survey
研究股票首次被价值线投资调查评级后3天内的价格反应，发现存在显著异常回报且之后无持续反应，支持市场效率假说。
This study examines daily price reactions to initial reviews of securities by the Value Line Investment Survey. The reviews are found to convey information to the market as significant abnormal returns are found over a 3-day period around release of the information. Furthermore, there is no statistically significant subsequent price reation after this 3-day period, consistent with market efficiency.