FINRA (Financial Industry Regulatory Authority) is a non-governmental organization that functions as a self-regulatory body for brokerage firms and exchange markets in the United States. Formed in 2007 from the merger of the National Association of Securities Dealers (NASD) and parts of the New York Stock Exchange, it is authorized by the U.S. Congress to oversee the securities industry. FINRA's main role is to write and enforce rules for ethical conduct among all registered broker-dealer firms and registered brokers in the U.S., administer licensing exams for securities industry professionals, and ensure compliance with federal securities laws.

A FINRA member refers to any brokerage firm or individual broker who is registered and licensed to trade securities and operates within the U.S. securities industry. These members are subject to FINRA’s regulatory oversight, which includes adherence to its rules and standards, mandatory participation in its arbitration and mediation programs, and periodic financial and operational reporting. Membership with FINRA is a requirement for any firm or individual who engages in the business of buying or selling securities on behalf of others in the U.S.

FINRA's operations and responsibilities are distinct from those of the Securities and Exchange Commission (SEC), the primary government body responsible for enforcing federal securities laws and regulating the securities industry. While the SEC oversees and regulates all aspects of the securities industry, including FINRA itself, FINRA's role is more focused on day-to-day regulation, supervision, and enforcement of compliance with its own rules and those of the SEC among its members. Essentially, while the SEC sets the broader regulatory framework, FINRA works within this framework, focusing specifically on brokerage firms and registered brokers, to ensure they operate in an ethical and lawful manner. This includes safeguarding market integrity and protecting investors in private markets by overseeing transactions, monitoring for fraudulent activities, and educating investors.