This paper develops a novel dictionary-based measure to capture a firm’s exposure to antitrust enforcement. We classify antitrust exposure into four categories: collusion, mergers, market dominance, and labor-related unfairness. Our analysis reveals that firms’ antitrust exposure has gradually increased in recent years. Firms with stronger market power, higher profitability, and greater growth potential tend to exhibit higher levels of antitrust exposure. We also document that external regulatory enforcement contributes to variation in exposure levels. Importantly, our measure of antitrust exposure is predictive of future antitrust outcomes. Finally, we find that firms with higher exposure are more likely to engage in lobbying activities, potentially in an effort to mitigate the risks associated with antitrust enforcement.