Corporate customer concentration and stock price crash risk

Using a large sample of U.S. firms, we find that major corporate customer concentration is positively associated with a firm's future stock price crash risk. This positive relation is more pronounced when the supplier firms have made a higher level of relationship-specific investments, have a poorer information environment, and/or face lower customer switching costs. Our evidence suggests that exposure to an undiversified corporate customer base can have a negative bearing on a firm's crash risk.