What happened Cruise ship stocks gave back some of their recent gains on Thursday, as surging COVID-19 case counts threaten to delay the beleaguered industry's recovery. By the close of trading, shares of Carnival (NYSE: CCL) (NYSE: CUK), Royal Caribbean (NYSE: RCL), and Norwegian Cruise Line Holdings (NYSE: NCLH) were down 7.8%, 3.9%, and 3.4%, respectively. So what Cruise ship stocks surged on Monday after Pfizer and BioNTech said their experimental coronavirus vaccine could be more than 90% effective at preventing COVID-19. A safe and highly effective vaccine would be a boon for cruise ship operators, who have suffered billions in losses with their ships stuck at port due to coronavirus-related sailing restrictions. Cruise ship companies are burning through staggering amounts of their shareholders' capital. Image source: Getty Images. However, even if Pfizer and BioNTech receive regulatory approval, their vaccine may not be widely available until well into 2021. In the meantime, Carnival, Royal Caribbean, and Norwegian Cruise Line are burning through nearly $1 billion in cash per month in aggregate. Now what With COVID-19 case counts soaring in the U.S. and many international markets, health officials could choose to extend sailing restrictions into 2021. Royal Caribbean, Carnival, and Norwegian Cruise Line Holdings have all raised cash to survive such a scenario, but each month that goes by eats into their cash cushions, thereby increasing the risk for investors. 10 stocks we like better than CarnivalWhen investing geniuses David and Tom Gardner have a stock tip, it can pay to listen. After all, the newsletter they have run for over a decade, Motley Fool Stock Advisor, has tripled the market.* David and Tom just revealed what they believe are the ten best stocks for investors to buy right now... and Carnival wasn't one of them! That's right -- they think these 10 stocks are even better buys. See the 10 stocks *Stock Advisor returns as of October 20, 2020 Joe Tenebruso has no position in any of the stocks mentioned. The Motley Fool recommends Carnival. The Motley Fool has a disclosure policy.Source