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 mortgage and fleet-management company PHH (NYSE: PHH) had a nice tailwind today, gaining as much as 15% in intraday trading after a hedge fund revealed a large new stake in the stock.

So what: For many investors, the names Hayman Capital and Kyle Bass may not mean a whole lot. But for those invested in, or even just interested in, PHH, those names are the key today. Just a week ago, PHH's shares were swooning on the company's plans to sell new debt. Today, they're doing exactly the opposite after Bass' hedge fund Hayman revealed that it's snapped up a 7.9% stake in PHH.

In short, Bass is a tack-sharp money manager who made oodles of money betting against the financial world ahead of the housing meltdown and financial crisis. And now he's taken a position in mortgage company PHH? You better believe that's interesting.

Now what: As smart as Bass may be, he's still just one investor and there's still the possibility that he could be very wrong on this one -- lest we forget John Paulson's epic 2011 meltdown. For that reason, it's probably a bad idea to rush to buy PHH today simply because Bass has jumped in. This could, however, be a good excuse for investors that had the stock on their radar to tune in more carefully to see if they can figure out what Bass found so appealing.

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