This paper extracts investor risk concern from the text of investormanagement communications and examines their impact on insider opportunistic sales. Utilizing data from listed companies holding online earnings communication conferences (OECCs) in China from 2007 to 2022, we find that heightened investor risk concern significantly curbs insider opportunistic sales, as manifested by reduced frequency and magnitude of such transactions. This governance effect of investor risk concern persists irrespective of motivation strength behind opportunistic sales. Further analysis reveals that the governance effect intensifies when investors exhibit superior information processing capabilities and when management’s risk statements better align with investor expectations. Notably, while mitigating opportunistic sales, elevated investor risk concern also significantly decreases the firm’s cost of equity capital. Our findings underscore the importance of fostering transparent and engaging investor-management communication in promoting effective corporate governance and mitigating insider misconduct.