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 Canadian fuel cell company Ballard Power Systems (NASDAQ:BLDP) sank 11% today after its quarterly results and outlook disappointed Wall Street.

So what: The stock has soared over the past year on rapidly rising fuel-cell adoption, but today's first-quarter revenue miss -- top line increased 13% to $14 million against the consensus of $15.3 million -- coupled with in-line guidance is forcing analysts to scale back their expectations a bit. While Ballard's net loss narrowed to $3.8 million from $7.9 million in the year-ago period, it isn't improving fast enough in Wall Street's eyes to justify the recent price surge.

Now what: Management reaffirmed its full-year guidance for breakeven adjusted EBITDA on revenue growth of about 30%. "Our Q1 results reflect continued improvement in key metrics, consistent with our business outlook and full-year guidance for 2014," President and CEO John Sheridan said in a press release. "Also, after the quarter we were pleased to close a strategic transaction with United Technologies, giving Ballard a commanding industry position in fuel cell intellectual property and strengthening our ability to grow shareholder value." More important, with the stock now off about 55% from its 52-week high, Mr. Market might finally be offering enterprising Fools a decent chance to buy into those growth prospects.

Brian Pacampara has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.