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 snack-food maker Diamond Foods (Nasdaq: DMND) were looking spoiled today as investors knocked shares down as much as 25% in intraday trading after the company provided an update on its ongoing internal investigation.

So what: Diamond's probe, which revolves around payments to walnut growers and related accounting policies, has already led to the delay of the company's acquisition of Procter & Gamble's (NYSE: PG) Pringles business. On Friday, shares of Diamond were soaring after positive comments from a Wall Street analyst suggested that concerns over the investigations were overblown.

The company's update today calls that assessment into question, noting that the investigation will likely stretch into February and will cause the company to miss the filing deadline for its fiscal first quarter SEC filing.

Now what: When Mr. Market is freaking out and rushing for the exits, it's often a good time for more sober investors to move in and take advantage of his hysteria. Diamond in particular may be an interesting target to try to pick up on the cheap because for conservative, long-term-oriented investors, branded snack foods can be an attractive category. There's certainly the risk that this mess turns out to be even worse than it looks, but as the market continues to drag down the stock's price tag, investors are increasingly compensated for taking on that risk.

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This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.