What happened

Shares of FireEye Inc. (NASDAQ:FEYE) fell 16.4% in November, according to data from S&P Global Market Intelligence, after the cybersecurity leader followed better-than-expected quarterly results with underwhelming forward guidance.

To be sure, FireEye plunged more than 10% on Nov. 2, 2017 alone -- the first trading day after its report -- then continued to drift lower throughout the rest of the month.

A glowing lock sitting on top of a grid of numbers, cybersecurity image

IMAGE SOURCE: GETTY IMAGES

So what

More specifically, FireEye's third-quarter revenue rose 1.7% year over year to $189.6 million, and translated to an adjusted net loss of $6.5 million, or $0.04 per share. Those figures might not sound encouraging at first glance. But they were comfortably ahead of FireEye's guidance, which called for revenue of $183 million to $189 million, and an adjusted per-share loss of $0.06 to $0.09.

To be sure, FireEye CEO Kevin Mandia noted the company's billings and operating cash flow were also well above expectations, and the company's cost structure is now more appropriate following a restructuring over the past year. Mandia also expressed his belief that FireEye's cutting-edge Helix cybersecurity platform promises to accelerate multi-product adoption and drive long-term subscription billings growth.

Now what

Nonetheless, FireEye told investors to expect fourth-quarter revenue of $190 million to $196 million. That's good for growth of 4.5% at the midpoint, but fell below Wall Street's expectations at the time for sales at the high end of that range. FireEye also anticipates an adjusted net loss ranging from breakeven to $0.03, which was roughly in line with consensus estimates.

To be fair, FireEye management admitted during its call with analysts that this guidance was conservative, as several large subscription deals in its pipeline turned out to have shorter-than-expected contract lengths. But that's hardly indicative of an underlying problem with FireEye's core business.

As such, and keeping in mind FireEye has made a habit of underpromising and overdelivering, I think this pullback could represent a compelling buying opportunity for long-term investors.

Steve Symington has no position in any of the stocks mentioned. The Motley Fool recommends FireEye. The Motley Fool has a disclosure policy.