Glancy Prongay & Murray LLP Announces Investigation of Graphic Packaging Holding Company (GPK) on Behalf of Investors

LOS ANGELES--(BUSINESS WIRE)--Glancy Prongay & Murray LLP, a leading national shareholder rights law firm, today announced that it is investigating potential claims against the board of directors of Graphic Packaging Holding Company (“Graphic Packaging” or the “Company”) (NYSE: GPK) concerning whether the board breached its fiduciary duties to shareholders. IF YOU ARE A GRAPHIC PACKAGING HOLDING COMPANY (GPK) SHAREHOLDER, CLICK HERE TO PARTICIPATE. What Happened? In December 2025, a shareho