An issue barreling toward the U.S. Supreme Court made an en banc pit stop at a federal appeals court in Washington, D.C., where judges heard oral arguments on a constitutional challenge targeting the SEC's administrative law judges.

The U.S. Court of Appeals for the D.C. Circuit didn't tip its hand Wednesday but seemed leery of upsetting the current system of ALJs. The case, Lucia v. Securities and Exchange Commission, asks whether the ALJs are unconstitutionally hired.

After Lucia, the court heard another round of arguments en banc in a case challenging a different agency, the Consumer Financial Protection Bureau. That case focused on whether the CFPB's leadership structure, which features a single director, violates the Constitution.