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 auto repair company Monro Muffler Brake (Nasdaq: MNRO) jumped 10% today after the company released earnings.

So what: Earnings in the fourth quarter were slightly above expectations at $0.26 per share versus estimates of $0.24 from analysts. But revenue fell well below estimates of $155.1 million when they hit just $150.8 million. But investors are looking past that today to the bottom line.

Now what: Management said that aging vehicles in the U.S. would offset a decline in miles driven because of high gas prices. That gave them confidence to give earnings outlook that was in line with expectations and revenue outlook that topped expectations for 2012. Still, at the top end of expectations Monro would be priced at an 18 forward P/E ratio, so I'm not jumping on the valuation today.

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