Just before earnings season gets ready to kick into high gear, a few major tech stocks made headlines this week. Facebook (META 2.98%) made a big change to its news feed that sent its stock tumbling, one analyst shared a bullish take on Amazon.com's (AMZN 1.30%) smart-speaker opportunity, and estimates highlight an impressive year for Apple's (AAPL 0.64%) Mac business.

Facebook stock tumbles

On Friday, Facebook stock fell about 5%, after the company announced a change to its news feed that would give greater priority to posts from friends and family. The change will deprioritize public content, including videos and posts from publishers and businesses. Notably, Facebook also said this move could mean users spend less time on its site.

A woman using a smartphone while holding a coffee

Image source: Getty Images.

"As we make these updates, pages may see their reach, video watch time, and referral traffic decrease," Facebook said. 

Since ad revenue not only accounts for nearly all of Facebook's revenue but also is the company's biggest growth driver, it's easy to see why this move could spook investors.

Obviously, Facebook hopes this change pays off over the long haul, sparking more loyal users and greater user satisfaction. But even in the near term, there could be benefits. In a post about the change, Facebook CEO Mark Zuckerberg said he expects the time users spend on Facebook will be more valuable after the change.

Amazon's big opportunity

Amazon has led the charge with smart speakers, as was evident over the holidays, when Echo products outsold all other items on the e-commerce company's website. Tens of millions of Alexa-enabled devices were sold during the company's record holiday shopping season, Amazon said in an update after Christmas. 

With this momentum in the rearview mirror, Stifel Nicolaus analyst Scott Devitt (via Tech Trader Daily) released a bullish price target for Amazon stock of $1,425 and a buy rating, noting that Amazon's dominance in smart speakers looks poised to continue. He estimated that Amazon has 70% of the smart-speaker market and will generate $15 billion to $17 billion of revenue from the Echo family of devices by 2020.

Apple's Mac business gains market share

Research firms IDC and Gartner estimate that Apple's strong fiscal 2017 for its Mac business continued into the fourth quarter of the calendar year. (Apple's fiscal 2017 ended on Sept. 30.) Both IDC and Gartner believe that fourth-quarter Mac sales helped the tech giant gain market share and grow unit sales during the sixth consecutive calendar year of declining PC shipments globally. In addition, both research firms show Apple rising to become the fourth largest PC maker in 2017, up from the fifth largest in 2016.

iMac Pro

iMac Pro. Image source: Apple.

In Apple's fiscal 2017, Mac posted record segment revenue, surging 25% year over year. During the fiscal year, Apple's recently redesigned MacBook Pro and a strong back-to-school season were key growth drivers for the segment. In the fourth calendar quarter of 2017, or Apple's first fiscal quarter of 2018, Apple's Mac business was probably helped by the Dec. 14 launch of its long-awaited iMac Pro.