We attempt to explain investor underreaction to earnings news using the newly documented refinement of the disposition effect, which is the V-shaped net selling propensity (VNSP). Using a novel data set containing stock-level information on the trading activities of different types of investors, we find that both large unrealized capital gains and losses positively predict subsequent stock returns in Korean stock markets. Furthermore, investors’ net selling propensity affects stock price drift after earnings announcements. Among good news stocks, postannouncement drift is more pronounced when they suffer from stockholders’ higher net selling propensity. Furthermore, these empirical results hold only when we construct a VNSP based on individual trading activity. Interestingly, the classic disposition effect does not induce underreaction to earnings news in our data set.