The cruise-line leader looks undervalued, relative to its growth potential. Carnival (CCL 0.07%), the world's largest cruise-line operator, was in dire straits five years ago. As the pandemic disrupted global travel and tourism, it was forced to idle its ships, take on billions of dollars in debt at high interest rates, and issue more shares to stay solvent. In April 2020, Carnival's stock sank below $8 a share. That was a near 90% drop from its record high in January 2018 and marked its lowest closing pric ...