A challenge to the U.S. Securities and Exchange Commission's powers to protect investors from fraud comes before the Supreme Court on Wednesday in another in a series of legal attacks against federal agencies that regulate financial markets. The justices are due to hear arguments in an appeal by President Joe Biden's administration of a lower court's ruling restricting the SEC's power to enforce securities laws through the agency's longstanding in-house tribunal system. The case involves hedge fund manager George Jarkesy, who the SEC fined and barred from the industry after determining he had committed securities fraud.