Although most major tech firms have already turned in their quarterly earnings, several key companies have yet to report. This week, earnings releases from Qualcomm (NASDAQ:QCOM), FireEye (NASDAQ:FEYE), Zynga (NASDAQ:ZNGA) and Activision Blizzard (NASDAQ:ATVI) should be among the most notable events in the tech space.

Qualcomm: Is the chip industry in for a rough ride?
Mobile chip giant Qualcomm has been a fairly disappointing investment in 2014, under-performing the broader S&P 500. It could, however, close the gap later this week: Qualcomm is set to report its fourth quarter results on Wednesday. Analyst estimates call for the company to earn $1.31 per share on revenue of $7.02 billion -- both figures would represent a solid increase from the prior year.

Early last month, shares of chip stocks --including Qualcomm -- fell after rival Microchip warned that the industry was on the verge of a significant downturn. If so, Qualcomm's investors could be disappointed with the quarter.

Samsung, one of Qualcomm's biggest customers, has seen its profits collapse as demand for its mobile products declines. Fortunately for Qualcomm, many of Samsung's competitors in the space -- including fast-rising Xiaomi -- use Qualcomm chips in their competing devices.

FireEye's terrible year could continue
Qualcomm's under-performance has been downright mild compared to FireEye, which has lost more than 60% of its value since the beginning of March. The maker of security software has been unprofitable since its public debut in late 2013, and analysts don't expect that to change this quarter: When it reports earnings on Tuesday, estimates call for FireEye to have lost $0.56 per share on revenue of $116 million.

FireEye remains a speculative investment, but its business is growing rapidly. Still, many investors are actively betting against the firm: Its short interest has soared in recent months, and more than 20% of outstanding shares have been bet against.

Analysts expect another loss at Zynga
Investors in Zynga are looking for the social game maker to show signs of a turnaround: CEO Don Mattrick has now been on the job for nearly six quarters. Mattrick should be on the company's earnings call on Thursday, following the release of Zynga's third quarter results.

As Zynga has been unprofitable for the majority of its history, it lacks a price-to-earnings ratio. Like FireEye, that isn't expected to change this quarter: Analyst estimates call for Zynga to lose $0.01 per share on revenue of $171 million.

Zynga has been a tremendously disappointing stock, both this year and for the majority of its history as a public firm. Year-to-date, Zynga shares are down more than 32%, and have fallen more than 73% since it began trading in late 2011. In its relatively short history, Zynga has gone through a number of shifts, including various major acquisitions and significant management turnover. At current levels, Zynga is near its all-time low.

How big was Activision's Destiny?
Video game giant Activision will report earnings on Tuesday. Analysts are looking for the company to have earned $0.13 on revenue of around $1 billion. It won't be the most vital quarter for Activision -- the upcoming holiday season should be far more influential -- but investors should learn how Activision's latest hit video game, Destiny, performed at retail.

Activision has had a solid year, but a bad quarter -- shares are down more than 11% over the last three months. Most of that loss appears to have been sparked by Destiny's critical reception. The game, from the creators of Halo, garnered a relatively modest 76 on Metacritic, a review aggregator.

But do reviews matter? If they managed to keep gamers away, Activison's results could suffer. A strong reception for Destiny, however, should bode well -- both for this quarter, and for the game's planned sequels.

Sam Mattera owns shares of Activision Blizzard. The Motley Fool recommends Activision Blizzard and Apple. The Motley Fool owns shares of Activision Blizzard, Apple, and Qualcomm. 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.