We are a diversified global brokerage and financial services firm providing execution, risk management and advisory services, market intelligence and clearing services across asset classes and markets around the world. We help our clients to access market liquidity, maximize profits and manage risk. Our revenues are derived primarily from financial products and advisory services intended to fulfill our clients' commercial needs and provide bottom-line benefits to their businesses. Our businesses are supported by our global infrastructure of regulated operating subsidiaries, our advanced technology platform and our team of more than 2,000 employees as of September 30, 2019. We believe our client-first approach differentiates us from large banking institutions, engenders trust and has enabled us to establish leadership positions in a number of complex fields in financial markets around the world.
We offer a vertically integrated product suite, including high-touch execution, electronic access through a wide variety of technology platforms in a number of important global markets, and insightful market intelligence and advice, as well as post-trade settlement, clearing and custody services. We believe this is a unique product suite offering outside of bulge bracket banks, which creates sticky relationships with our clients. Our business model has created a revenue stream that is diversified by asset class, client type and geography, with a significant portion of recurring revenue derived from monetizing non-trading client activity including consistent and predictable interest and fee earnings on client balances, while also earning both commissions and spreads as clients execute transactions across our financial network.
We currently serve more than 20,000 commercial and institutional clients, located in more than 130 countries. We believe we are the third largest independent, non-bank futures commission merchant ("FCM") in the United States ("U.S.") as measured by our $2.2 billion in required client segregated assets at our U.S. FCM as of September 30, 2019, and one of the top ranked market makers in foreign securities by dollar volume as determined through the three-year period ended December 31, 2018, making markets in approximately 5,000 different foreign securities. We are one of only nine Category One ring dealing members of the London Metals Exchange (the "LME"). Our clients include commercial entities, asset managers, regional, national and introducing broker-dealers, insurance companies, brokers, institutional investors and professional traders, commercial and investment banks and government and non-governmental organizations ("NGOs"). We believe our clients value us for our attention to their needs, our expertise and flexibility, our global reach, our ability to provide access to liquidity in hard to reach markets and opportunities, and our status as a well-capitalized and regulatory-compliant organization. Our correspondent clearing and independent wealth management businesses include approximately 70 correspondent clearing relationships representing more than 80,000 underlying individual securities accounts as of September 30, 2019.