Whenever the United States is hereafter injured in its business or property by reason of anything forbidden in the antitrust laws it may sue therefor in the United States district court for the district in which the defendant resides or is found or has an agent, without respect to the amount in controversy, and shall recover threefold the damages by it sustained and the cost of suit. The court may award under this section, pursuant to a motion by the United States promptly made, simple interest on actual damages for the period beginning on the date of service of the pleading of the United States setting forth a claim under the antitrust laws and ending on the date of judgment, or for any shorter period therein, if the court finds that the award of such interest for such period is just in the circumstances. In determining whether an award of interest under this section for any period is just in the circumstances, the court shall consider only—

(1) whether the United States or the opposing party, or either party’s representative, made motions or asserted claims or defenses so lacking in merit as to show that such party or representative acted intentionally for delay or otherwise acted in bad faith;

(2) whether, in the course of the action involved, the United States or the opposing party, or either party’s representative, violated any applicable rule, statute, or court order providing for sanctions for dilatory behavior or otherwise providing for expeditious proceedings;

(3) whether the United States or the opposing party, or either party’s representative, engaged in conduct primarily for the purpose of delaying the litigation or increasing the cost thereof; and

(4) whether the award of such interest is necessary to compensate the United States adequately for the injury sustained by the United States.