My thesis consists of three chapters on information economics and financial economics.Chapter 1:Many decentralized over-the-counter (OTC) markets have recently become subject to new regulations requiring transparency. I build up an information model that features bilateral trade in a double auction, endogenous public signal, and inter-dealer network formation to study the effect of TRACE on the inter-dealer markets. In the trading stage, I study the private information diffusion process and endogenize the public information contained in the disseminated trading price. I show that in markets with a relatively low degree of information asymmetry, post-trade transparency makes the adverse selection more severe and reduces the surplus from asse...