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 storage drive maker Fusion-io (FIO.DL) plummeted 22% today after its quarterly results and outlook missed Wall Street expectations.

So what: The stock has plunged over the past year on sluggish demand, and today's fourth-quarter results -- loss widened to $23.8 million as revenue slipped to $106.05 million -- coupled with downbeat guidance only reinforce that trend. In fact, Fusion-io posted a negative operating margin of 22.4% in the quarter on a 51% spike in marketing costs, suggesting the competitive environment is only getting more intense.

Now what: Management now sees full-year revenue growth of 20%, implying sales of about $519 million versus Wall Street's view of $564 million. "To continue to maintain our market leadership, we will increase our focus on our go-to-market strategy, product portfolio and our partnerships as we help customers around the world unlock the business value in real-time information intelligence," said CEO Shane Robison. Of course, given the strong competitive headwinds facing Fusion-io at this point, I'd wait for even more of a pullback before buying into that bullishness.