Block ownership and firm-specific information

This study examines the impact of block ownership on the firm's information environment. Previous research shows that stock price efficiency depends on the cost of acquiring private information, as well as on the precision of this information. Blockholders have a clear advantage over diffuse, atomistic shareholders in terms of the precision and acquisition cost of their private information. We hypothesize that this informational advantage will manifest itself primarily in the firm-specific component of stock returns. Our empirical findings confirm that blockholders increase the probability of informed trading and idiosyncratic volatility, and decrease the firm's stock return synchronicity. These results hold for both inside and outside blockholders, but are insignificant for blocks controlled by employee stock ownership plans (ESOPs). Overall, our findings support the contention that ownership structure plays a significant role in shaping the firm's information environment. (c) 2008 Elsevier B.V. All rights reserved.