It was a busy week in tech. The biggest news was likely Amazon's (NASDAQ:AMZN) substantial expansion to its lineup of smart-assistant Echo devices. In addition, Facebook (NASDAQ:FB) said its Instagram video- and photo-sharing service hit another key milestone on its path to 1 billion users, and Roku (NASDAQ:ROKU) and Blackberry (NASDAQ:BBRY) saw their stocks surge higher.

Here's what you need to know.

Amazon wants to own the smart-speaker market

Amazon clearly isn't interested in giving up its early lead in the smart-speaker market. The e-commerce giant hosted a surprise event on Wednesday where it unveiled new echo devices and an updated Fire TV set-top box.

Amazon's new Echo Spot

Echo Spot. Image source: Amazon.com.

The new products fortified Amazon's offering in the smart-speaker category it made popular with the launch of its first Amazon Echo in 2014.

Amazon unveiled a second-generation version of the original Amazon Echo with improved sound and performance and a more compact design, a new Echo Plus with a built-in hub for easily connecting to smart-home devices, an Echo Spot that includes a 2-inch screen and a camera, and more.

Amazon's update to its Fire TV was also timely as it added support for 4K videos ahead of the holidays and just after Apple launched a new version of its set-top box with support for 4K streaming.

Instagram hits 800 million users

Facebook's Instagram hit 800 million monthly active users during the week. Growth in the social-network service has been astounding. Instagram has doubled its monthly active users in just two years.

Instagram celebrates 800 million users

Image source: Instagram.

Instagram Monthly Active Users

Date

800 million

September 2017

700 million

April 2017

600 million

December 2016

500 million

June 2016

400 million

September 2015

300 million

December 2014

200 million

March 2014

Data from Instagram's official blog. Table by author.

Instagram also said it now boasts an impressive 500 million daily active users. 

BlackBerry surprises investors

BlackBerry stock popped on Thursday, rising about 15% after the company reported better-than-expected results for its fiscal 2018 second quarter. Shares continued higher as the week went on, ending the week with a total gain of 22%.

BlackBerry's record $196 million in quarterly revenue for its software and services division, as well as the company's surprising profit on a non-GAAP basis, surprised investors and provided evidence of the company's strong progress in transitioning away from hardware. The profitability was helped by a record gross margin of 76% on a non-GAAP basis and 74% on a GAAP basis.

Roku's IPO surges

Finally, streaming-TV company Roku made its public debut this week on the Nasdaq. Shares soared more than 60% higher during the week after the company's IPO was priced at $14. Roku stock finished the week trading at $26.54, with a market capitalization of about $2.5 billion.

The "Roku Channel" shown on a TV screen

Image source: Roku.

Roku has its work cut out for it. Not only is it competing in a crowded space with Apple and Amazon -- and both companies recently updating their streaming-TV set-top boxes -- but Roku also needs to focus on achieving profitability. In the six months ending June 30, Roku reported an operating loss of $21.2 million.

Daniel Sparks owns shares of Apple and Facebook. The Motley Fool owns shares of and recommends Amazon, Apple, and Facebook. The Motley Fool has a disclosure policy.