Why do some markets remain liquid even when there is a positive gain from trade? In order to understand the real determinants of market liquidity in decentralized markets, we are going to analyze this question in a competitive market setting when both search frictions and adverse selection play roles. In a dynamic environment with heterogeneous sellers and buyers, we investigate the role of market frictions and how adverse selection leads to the distortion of equilibrium market liquidity. The resulting friction therefore prohibits resources from reallocating efficiently. In the application of capital reallocation, we further show that this trading friction can generate significant economic fluctuations.