The Commodity Futures Trading Commission (CFTC) (defendant) regulates the trading of commodity futures. Disgruntled customers may seek reparations from the CFTC for a broker’s violations of the Commodity Exchange Act (CEA) or CFTC regulations. The CTFA promulgated a regulation that allowed it to adjudicate any counterclaims that the broker might assert against a consumer if such counterclaims arose out of the same transaction or series of transactions set forth in the customer’s complaint. Such counterclaims were not mandatory; brokers could pursue their action against the customer in state court as a contract action. Mr. Schor (plaintiff), a customer, filed a complaint against a broker, Conti Commodity Services, Inc. (Conti), for numerous violations of the CEA. In addition to defending itself from Schor’s claims, Conti filed a counterclaim against Schor in the CFTC reparations proceeding. The CFTC ruled in favor of Conti, and Schor sought judicial review. The court of appeals dismissed Conti’s counterclaim on the ground that the CFTC’s authority to adjudicate Conti’s common law claims violated Article III of the Constitution. The United States Supreme Court granted certiorari.