CNBCSupreme Court backs American Express in credit card fee case; shares popCNBCIn a five to four ruling, the Supreme Court said Amex rules regarding its services for merchants don't violate federal antitrust law. Shares jumped 1.7 percent. The case centered on the fees that credit card companies charge retailers for processing ...UPDATE 1-US Supreme Court backs American Express in merchant fee disputeReutersSupreme Court: Amex Anti-Steering Does Not Run Afoul Of Antitrust LawPYMNTS.comAmerican Express Wins as Supreme Court Tosses Credit-Card SuitBloombergU.S.