This paper studies the corporate governance and asset pricing implications of investors owning blocks in multiple firms. Common wisdom is that multi-firm ownership weakens governance because the blockholder is spread too thinly. We show that this need not be the case. In a single-firm benchmark, the blockholder governs through exit, selling her stake if the firm underperforms. With multiple firms, the blockholder may sell even a value-maximizing firm, to disguise her exit from another underperforming firm as being motivated by a portfolio-wide liquidity shock. This reduces the manager's effort incentives and weakens governance. On the other hand, governance can be stronger, because selling one firm and not the other is a powerful signal of underperformance. Common ownership leads to firms' stock prices being correlated, even if their fundamentals are uncorrelated. We derive empirical predictions for the direction of correlation and for whether governance is stronger or weaker with multiple firms.
