One detail in the latest earnings suggests why some deep-value investors may see more upside than the stock chart implies.New York City-based Atlantic Investment Management initiated a new position in Graphic Packaging Holding Company (GPK), adding 645,584 shares valued at approximately $12.6 million, according to a November 14 SEC filing.What HappenedAccording to a filing with the Securities and Exchange Commission dated November 14, Atlantic Investment Management disclosed a new stake in Graphic Packaging ...