Costco shareholder files stock option lawsuit (Lexington Herald-Leader) A Costco shareholder has filed a lawsuit against the wholesale club company, claiming its insiders were involved in a scheme to illegally backdate stock options. The suit claims some current and past Costco insiders and executives manipulated information allowing them to be "unjustly enriched at the expense of and detriment of Costco" for several years. Shareholder Sandra Donnelly filed ... [News Source]