Wall Street

Image source: Getty Images.

Stocks couldn't hold on to their earlier gains on Friday as an afternoon decline left both the Dow Jones Industrial Average (DJINDICES:^DJI) and the S&P 500 (SNPINDEX:^GSPC) indexes finishing with minor losses.

Today's stock market

Index

Percentage Change

Point Change

Dow

(0.24%)

(42.39)

S&P 500

(0.17%)

(3.48)

Data source: Yahoo! Finance.

The United States Oil Fund (NYSEMKT:USO) fell by more than 1% after crude oil prices hit a six-week low. Meanwhile, the iShares MSCI Emerging Index Fund (NYSEMKT:EEM) ticked down in concert with another slight decline in Asian markets.

FireEye (NASDAQ:FEYE) was one of the biggest winners on the market, while GoPro (NASDAQ:GPRO) endured yet another drop to add to a rough year for its shareholders.

FireEye's cost cuts

Cybersecurity specialist FireEye notched a 16% gain after posting surprisingly strong quarterly numbers. Bookings rose by 2% to just over $214 million as revenue climbed 13% to $186 million. Both figures edged past management's early August guidance.

Cyber Security

Image source: Getty Images.

CEO Kevin Mandia and his executive team continued to make big strides at lowering the software maker's cost structure to better align with its growth pace. Operating expenses fell as a percentage of sales so that net loss improved to $0.75 per share from $0.88 per share last year.

"We made significant progress strengthening FireEye financially and operationally in the third quarter," Chief Financial Officer Mike Berry said in a press release. A key win was reducing the expense base by over $10 million to produce the company's best operating margin yet.

FireEye remains unprofitable, having produced losses of $418 million so far this year. Yet the company sees demand trends improving. It boosted its sales and billings forecasts and sees net loss of $1.15 per share, marking an improvement over the $1.30 loss it last projected. For a stock that was down over 30% in the three months headed into this week's release, that glimmer of good news was enough to send shares significantly higher.

GoPro's production problems

GoPro investors endured a wild ride on Friday, as shares slumped by as much as 18% before surging into positive territory -- and then falling again to end the day down 6.5%. The intense volatility came as investors digested the action-camera maker's latest quarterly report.

Gpro

Image source: GoPro.

In that announcement, GoPro revealed that sales fell by 40% as it produced an operating loss of $115 million, compared to a $27 million profit in the year-ago period. Gross profit also took a big hit, slumping to 40% of sales from 47% as the company spent heavily on developing and supporting its latest lineup of products.

Management has high hopes that the new devices, led by the Hero 5 camera and the Karma drone, can perform well enough to return the company to profitability in the holiday season quarter. "These are the best products we've ever made and consumer demand is strong," CEO Nicholas Woodman said in a press release.

However, executives' updated outlook implies a tough sales environment ahead. GoPro lowered its full-year forecast to $1.28 billion from the $1.42 billion it projected back in July. Management blamed production problems that have led to supply bottlenecks for both the Karma and the Hero 5, and while that's not as bad as demand shortfalls, it still highlights the risks around a strategy that requires the company design, produce, and market a string of successful consumer devices in a rapidly changing industry.

Demitrios Kalogeropoulos has no position in any stocks mentioned. The Motley Fool owns shares of and recommends FireEye and GoPro. The Motley Fool has the following options: short January 2019 $12 calls on GoPro and long January 2019 $12 puts on GoPro. 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.