The term AMEX Counterpart refers to four different entities: the SEC (Securities and Exchange Commission), COS (Commodity Futures Trading Commission), NASDAQ (National Association of Securities Dealers Automated Quotations) and NYSE (New York Stock Exchange). The SEC is a government agency that regulates the securities industry, while COS is an independent agency that regulates futures and options markets. NASDAQ is an electronic stock exchange, and NYSE is a physical stock exchange. Together, these four entities form the AMEX Counterpart, which provides a comprehensive regulatory framework for the financial markets.