On Tuesday the US Supreme Court heard oral arguments on this question:
If an employee is fired for reporting alleged misconduct to his managers, but does not report anything to the SEC, does he get the "whistleblower" protections of the Dodd-Frank Act?
For a thorough and insightful review of the arguments, I recommend "Argument analysis: Don’t just whistle while you work – Dodd-Frank whistleblowers may need to pucker up for the SEC" by George Washington University School of Law Professor Theresa Gabaldon.
I agree with her conclusion: "There may be good reasons one doesn’t bet on Supreme Court cases. There also are good reasons to suspect that Digital Realty Trust walked away from yesterday’s argument whistling the more cheerful tune.
For a quicker review of the arguments: Internal whistleblowers: SCOTUS argument summary