What: Shares of Royal Caribbean Cruises Ltd (RCL 1.23%) fell 19% in January according to S&P Capital IQ data, and the plunge hasn't stopped with shares now down 27% since the end of 2015.

So what: The investing theme in January was concern that the global economy would slow down, particularly in China, where much of the world's growth has come from in the last decade. As those fears spread, investors sold hospitality stocks like Royal Caribbean on concerns that revenue and earnings wouldn't meet expectations in future years.

This was confirmed on Tuesday, when management said that 2016 earnings would be $5.90 to $6.10 per share, well below the $6.27 per-share figure that Wall Street analysts expected. But that's also an increase from the $4.83 that the company earned in 2015.  

Now what: This looks like a case of expectations just getting out of hand for Royal Caribbean Cruises. The company has had a lot of tailwinds the past few years as the economy improved, discretionary spending increased, and fuel costs plunged. But growth is now slowing, and expectations will have to adjust, as well.

While expectations may have been too high at the end of 2015, it looks like they may have swung too low now. Shares trade at just 12 times the midpoint of expected 2016 earnings, and those earnings are growing. I think that's a decent value for long-term investors, even if consumer spending slows.