We investigate the relation between organization structure and the information content of short sales, focusing on founder- and heir-controlled firms. Our analysis indicates that family-controlled firms experience substantially higher abnormal short sales prior to negative earnings shocks than nonfamily firms. Supplementary testing indicates that family control characteristics intensify informed short selling. Further analysis suggests that daily short-sale interest in family firms contains useful information in forecasting stock returns; however, we find no discernable effect for nonfamily firms. This analysis provides compelling evidence that informed trading via short sales occurs more readily in family firms than in nonfamily firms.