The administration said it would no longer defend a federal appeals court decision that upheld the commission’s use of in-house judges.
The case could insulate publicly traded companies from some whistle-blower lawsuits.
The move offers new hope for retailers trying to reduce the $50 billion in fees they pay to credit-card companies each year.
Justices suggested the agency is bound by a give-year statute of limitations on disgorgements.
The court will enter into the debate over investors' ability to sue companies for limiting disclosure information.
Several justices said that ruling had changed decades-old standards for insider trading.