In the chapter ``When to Introduce Electronic Trading Platforms in Over-the-Counter Markets?'' An equilibrium in a market is determined in which traders have the choice between using an electronic platform with a request-for-quote protocol or calling a dealer directly. The main takeaway is that platforms increase the bargaining power of traders with search costs, thereby increasing their market participation and potentially also welfare. Another friction that affects trading in OTC markets are informational frictions. market participants may learn from trading activity on platforms and trade on that information in other trading venues. The interplay between an electronic trading platform in the dealer-to-customer market and the interdealer market is analysed in the chapter ``Electronic Trading in OTC Markets vs. Centralized Exchange.'' In that chapter, a two-tiered OTC market is compared with a fully centralized market, showing that informed traders may prefer the two-tiered structure in order to benefit from their information. This ability of decentralized OTC markets to deal with asymmetric information is also a major benefit of OTC markets compared to exchange markets in welfare considerations. In the chapter ``Informed Traders and Dealers in the FX Forward Market,'' it is analyzed whether such informational frictions exist, whether dealers are able to mitigate those by charging different markups to different clients and whether we behavior consistent with the alleviation of informational frictions.