Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of cruise-ship operator Carnival (NYSE: CCL) were well under water today, falling as much as 15% after Costa Concordia, one of the company's ships, capsized off the Italian coast Friday.

So what: Investors who have been tuned into the news have no doubt seen pictures from the terrible disaster that has thus far left 11 people confirmed dead. The Costa Concordia, which is part of Carnival's Costa Crociere arm, slammed into rocks and capsized off the coast of the island of Giglio. The company has said the accident will cost it at least $90 million, as the Costa Concordia will be out of commission for the rest of the year.

Now what: There is good reason for investors to be concerned. Obviously there are going to be plenty of direct costs from the Costa Concordia crash. Looking ahead, though, there is also the concern that potential Carnival customers will find their cruise-taking excitement dulled by the frightening images of the massive cruise ship on its side, halfway engulfed by the Mediterranean Sea. Only time will tell how this will play out for Carnival, but with news cameras currently trained on the company and this awful mishap, we are currently likely either at or near the point of maximum pessimism as far as the stock market is concerned.

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