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 diet specialist Weight Watchers (NYSE: WTW) climbed 12% today on extraordinarily high volume.

So what: The spike comes on the heels of its quarterly results Friday, in which Weight Watchers did just about everything beautifully except impress investors. The shares sank 10% despite announcing analyst-topping earnings and full-year guidance, but with a weekend to think about it, Mr. Market seems to be admitting the error of his ways.  

Now what: Weight Watchers looks like a decent opportunity. With all signs pointing to a particularly prolonged upturn in subscriptions and Web-based sales, management has some pretty attractive tailwinds working in their favor. And with the shares continuing to trade at a reasonable valuation -- even after its massive year-to-date run-up -- there might still be room for shareholders to benefit.

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Fool contributor Brian Pacampara owns no position in any of the companies mentioned. Try any of our Foolish newsletter services free for 30 days.

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