Carnival Corporation (CCL) shares are set for a rough start on Thursday, plummeting 5.09% in pre-market trading. This decline follows a significant 6.89% drop during Wednesday's regular trading session, indicating persistent investor concerns in the cruise line industry.

The catalyst for this downturn appears to be Norwegian Cruise Line Holdings' announcement of a major debt refinancing transaction. On Wednesday, Norwegian revealed that its subsidiary had agreed to swap approximately $285.4 million of 5.375% exchangeable notes due 2025 for newly issued 0.875% exchangeable notes due 2030, along with a cash payment of about $51.6 million. To fund this cash component, the company issued around 2.7 million shares in a registered direct equity offering at $19.06 per share.

While Norwegian Cruise Line's refinancing move aims to extend its debt maturity profile, it has raised concerns about the financial health of the entire cruise industry. The negative sentiment is not limited to Carnival, as other major players in the sector are also feeling the impact. Royal Caribbean and Norwegian Cruise Line Holdings are both down about 4% in pre-market trading, suggesting a broader industry-wide sell-off as investors reassess the financial stability of cruise operators in the current economic climate.