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: Good news for Best Buy (NYSE: BBY) shareholders this morning turned into even better news for investors in its newest rival, hhgregg (NYSE: HGG). Q1 profits dropped at Best Buy but not as badly as expected, lifting the company's shares 6% in early trading -- and sending hhgregg up as much as 10%.

So what: Thinking about this logically, if two companies are rivals and one does better than expected, you might expect this to mean it stole market share from its rival -- bad news for hhgregg. On the other hand, it's just as logical to figure that if investors were worried Best Buy would do poorly in a poor retail environment, good results from Best Buy could portend better sales for everybody in retail, hhgregg included.

Now what: With hhgregg selling for 12 times earnings, pegged for 18% annual profits growth over the next five years, and now the recipient of maybe-good-news of faster-growing profits, a lot of folks will tell you the company's a screaming buy. I'm not one of those folks.

I find it worrisome that the faster hhgregg seems to grow, the worse its cash flow statement becomes. For years, hhgregg was a smart, free-cash-flow-positive operator. Last year, however, as store-opening costs ate up its cash, hhgregg turned free cash flow negative. GAAP profits are all well and good, but before I buy the stock, I'm going to need hhgregg to show me the money.

But that's just me. If you think hhgregg is as good a deal as many investors decided it was this morning, add the stock to your watchlist. See if this story plays out as planned.