In this paper, we develop a dynamic model of institutional share dumping surrounding control events. Institutional investors sometimes dump shares, despite trading losses, in order to manipulate share prices and trigger activism by "relationship" investors. These institutional investors are motivated to trade not only by trading profits but also by a desire to protect the value of their inventory and to disguise the quality of their own information. Relationship investor profit from targeting firms both by improving firm performance and by generating private information. (c) 2005 Elsevier B.V. All rights reserved.