This paper presents the results of 32 experimental markets designed to test hypotheses based on Wagenhofer's (1990) disclosure model. The model predicts the existence of multiple disclosure equilibria in cases where a manager balances the effects that disclosures can have on two sets of external agents: investors and an opponent. The experimental results support the partial-disclosure equilibrium over the full-disclosure option. Additionally, a lower level of disclosure was observed in those markets in which the discloser repeatedly interacted with information receivers. Lower disclosure reduces the level of proprietary costs which is beneficial to the information sender.