This thesis consists of five chapters. Chapter 1 is the preliminaries. Chapter 2 to chapter 4 are the three main chapters of this thesis, which covers the U.S. market, international market, and the Chinese market, respectively. Chapter 5 is the discussion. Chapter 1 is the preliminaries. It introduces the setting and motivations for the three topics covered in this thesis. Chapter 2 investigates how equity exchange-traded fund (ETF) ownership affects the cost of debt. I find that, by facilitating short-selling activities to execute disciplinary effects, equity ETF ownership decreases a firm's cost of debt. This negative association between equity ETF ownership and the cost of debt is more pronounced for firms with weaker information enviro...