We investigate if sell-side security analysts exhibit relative persistence in their stock picking ability. We find that analysts whose recommendation revisions earned the most (least) positive excess returns in the past continue to outperform (underperform) other analysts in the future. Further, we find that the market recognizes these performance differences in the five-day period surrounding the recommendation revision. This market reaction, however, is incomplete. Excess returns measured over the one and three trading months following the revision are significantly different from zero and positively associated with the analysts