Final answer:
The largest Self-Regulatory Organization (SRO) in the United States is the Financial Industry Regulatory Authority (FINRA).
Step-by-step explanation:
The largest Self-Regulatory Organization (SRO) in the United States is the Financial Industry Regulatory Authority (FINRA).
SROs are organizations that regulate certain industries or professions, setting standards and overseeing compliance with those standards. In the case of FINRA, it is responsible for regulating the securities industry in the US.
FINRA was created in 2007 when the National Association of Securities Dealers (NASD) and the regulatory functions of the New York Stock Exchange (NYSE) merged. It is tasked with protecting investors and ensuring fair and efficient markets.