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 farmer-focused retailer Tractor Supply (Nasdaq: TSCO) were plowing ahead today, rising 17% after the company reported second-quarter results.

So what: Companies don't have to produce good-looking results to top expectations and get investors excited. A company that's expected to do terrible can still see its stock spike if it reports results that are only pretty bad. But, for Tractor Supply, the second quarter not only beat expectations, but looked darn good on an absolute basis.

Revenue for the retailer rose nearly 10% from last year, to $1.3 billion, while same-store sales gained 7.1%. On the bottom line, earnings per share finished at $1.45, up 18% year over year. Wall Street analysts had been expecting just $1.39 in per-share profit on $1.3 billion in revenue. The company said that sales of consumable products for animals and pets were particularly strong during the quarter.

Now what: With half the year now in the history books, Tractor Supply's management updated its full-year outlook. For all of 2012, the company now expects total revenue of between $4.58 billion and $4.65 billion, which, at its midpoint, is down slightly from the previous forecast. The profit outlook though, was boosted to a range of $3.58 to $3.66, a near 2% increase at the midpoint.  

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