We identify an important channel, acquisitions of public targets, via which the governance through trading (GTT) improves firm values. The disciplinary effect of GTT is more pronounced for firms with higher managerial wealth-performance sensitivity and moderate institutional ownership concentration. Firms with higher GTT also have higher subsequent ROA, ROE, Tobin's Q, analysts forecasted EPS growth rate, and lower expected default risk. The effect is stronger after Decimalization. We conduct several exercises to rule out alternative explanations, such as institutional superior information, investor activism, and momentum. Additional tests show that the disciplinary effect of GTT only exists for less financially-constrained firms and non-all-cash M&As where the agency problem is more likely to be prevalent.