Image Source: Getty Images. What: Shares of cybersecurity company FireEye (NASDAQ: FEYE) slumped on Friday following the company's second-quarter report. FireEye reported mixed results relative to analyst expectations, but weak guidance and news of layoffs sent the stock 12% lower by 10:45 a.m. EDT. So what: FireEye reported second-quarter revenue of $175 million, up 19% year over year but about $6.6 million below the average analyst estimate. Billings rose just 10% year over year, to $196.4 million, well below the 23% growth posted during the first quarter. Non-GAAP loss came in at $0.33 per share, up from a per-share loss of $0.41 during the prior-year period, and $0.09 higher than analyst expectations. GAAP losses totaled $139.3. million, or $0.86 per share, compared to $133.6 million, or $0.87 per share, during the second quarter of 2015. In addition to reporting slower-than-expected revenue growth, FireEye slashed its guidance for the full year. Metric New Guidance Previous Guidance Revenue $716 million to $728 million $780 million to $810 million Non-GAAP billings $835 million to $855 million $975 million to $1,055 million Non-GAAP EPS ($1.32) to ($1.28) ($1.27) to ($1.20) Cash flow from operations No guidance given $70 million to $80 million Data Source: FireEye Q1 and Q2 earnings reports. Due to the company's slowing growth, a restructuring program was announced that will save FireEye at least $20 million in non-GAAP costs in the fourth quarter of 2016. The restructuring will include a reduction in the company's workforce. Now what: Once a fast-growing company valued at over $11 billion, FireEye is now worth just $2.45 billion after Friday's plunge. The stock has lost 85% of its value since peaking in early 2014. FEYE data by YCharts. FireEye's strategy up to this point has been to spend heavily on research and development, and sales in order to drive growth. The company has produced massive losses in the process, but revenue growth has impressed until recently. With FireEye now growing at a far slower rate, it can no longer justify its exuberant spending. CEO Kevin Mandia explained how the company's strategy will differ going forward: "We still have much work to do, but I am convinced that FireEye has the critical assets necessary for long term success, and that we are taking additional steps to achieve balanced growth and profitability." FireEye has become big enough that it can no longer produce the kind of growth that it has achieved in the past. The company will eventually need to figure out how to turn a profit, something that investors will likely care more about going forward in light of the slowing growth. A secret billion-dollar stock opportunity The world's biggest tech company forgot to show you something, but a few Wall Street analysts and the Fool didn't miss a beat: There's a small company that's powering their brand-new gadgets and the coming revolution in technology. And we think its stock price has nearly unlimited room to run for early in-the-know investors! To be one of them, just click here.Timothy Green has no position in any stocks mentioned. The Motley Fool owns shares of and recommends FireEye. 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.