Do some top executives matter more than others? Integrating insights from upper echelons and executive mobility research, we suggest that the functional roles performed by top executives shape their value to the firm. We examine the effects of interfirm executive mobility on firm survival for New York City advertising firms from 1924 to 1996. We find that, while losing any top executive is damaging, the loss of a top executive whose functional role focuses on internal firm processes is more detrimental to firm survival than losing a top executive whose functional role focuses on managing external exchange relationships. Additionally, in situations when multiple executives leave simultaneously, firms are more negatively affected when the group departing is functionally heterogeneous. Copyright © 2014 John Wiley & Sons, Ltd.