ICAP puts the icing on the cake for a whole bunch of traders. As one of the world's largest interdealer brokerages, ICAP is a wholesale broker of OTC derivatives, money markets, and securities, focusing on interest rates, commodities, foreign exchange, credit, emerging markets and equity derivatives markets. With operations in more than 30 countries, the firm is also a major interdealer broker in US Treasury notes. The company's electronic trading services provide direct trade execution and processing services to investment houses and major banks. ICAP also provides post-trade risk and information management services -- a fast-growing part of its business. Tullett Prebon agreed to buy ICAP's vocal broking business in late 2015.