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 electrode manufacturer GrafTech International (NYSE: GTI) plummeted 17% today after its quarterly revenue disappointed Wall Street.

So what: GrafTech's fourth-quarter EPS managed to slightly top estimates, but a big revenue miss -- $348 million versus the consensus of $363.4 million -- is triggering more demand concerns. Declining steel production in Europe continues to weigh heavily on the company, and judging from today's pullback, Wall Street doesn't expect the trend to let up anytime soon.  

Now what: I'd look into this big plunge as a possible buying opportunity. While sales volume will likely decrease in 2012, management fully intends to raise electrode prices 10%-15% to offset some of the pressure. With the stock flirting with its 52-week lows and trading at a single-digit forward P/E, GrafTech seems cheap enough to take a chance on.

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