You are referring to what is known as a "Qui Tam" lawsuit. These cases are almost always handled on a contingency basis. You are the plaintiff on behalf of the U.S. .The action is filed"under seal", so that the party being sued is not initially aware of the lawsuit. In an SEC action, the Office of the United States Attorney receives the complaint and ultimately determines if they will assume the prosecution of the action. If they do, then if the government is successful in obtaining a financial payment you will be awarded a percentage of the overall payment. Hope this helps you.
The responses provided to your questions are not legal advice, do not create any attorney client relationship, and are provided for informational purposes only.
The term "whistleblower" has many connotations. You could be, as noted previously, a party to what is called a "qui tam" action. You could also be seeking assistance as a Dodd-Frank whistleblower, which does not involve filing a lawsuit but DOES involve submitting a well-drafted, supported submission to the SEC with the hope of a "bounty" down the road. Some states also have their own "qui tam" statutes as well, which may or may not be applicable in your situation.
In the case of a Dodd-Frank submission, you can remain anonymous so long as you retain counsel for the submission. Many attorneys handle such submissions on a contingency basis with a modest up-front retainer.
There are, of course, those urgent instances where retention of counsel on an hourly basis is necessary to consult and communicate with regulators and law enforcement on your behalf. Just be aware that you can't blow the whistle on yourself in most cases. And if and when you do, have your counsel guide you along the way.
The foregoing is not legal advice nor is it in any manner whatsoever meant to create or impute an attorney/client relationship.