Refers to a supplemental type of insurance coverage available from some D&O insurers pursuant to which costs incurred by the insured company in investigating a demand by shareholders that the board of directors bring a claim on behalf of the insured company against certain directors and officers for alleged wrongdoing. Shareholders who wish to bring a derivative lawsuit on behalf of the company against directors and officers generally must first demand the board of directors to bring the claim against the directors and officers. Once that demand is made, the board on behalf of the company is required to thoroughly investigate the merits of the shareholders’ allegations and determine whether it is in the best interests of the company that the proposed claim be prosecuted against those directors and officers. Because that investigation is for the benefit of the company as a potential plaintiff, and not for the benefit of the target directors and officers as potential defendants, costs incurred in that investigation are not covered under a standard D&O insurance policy. If the insureds purchase the supplemental investigation cost coverage, the expenses incurred in investigating this shareholder derivative demand would be covered.