While IPOs might have garnered more attention, this year was also notable for its steady stream of acquisition dealsThe first half of 2019 ushered in $2 trillion in deal activity worldwide--$1.1 trillion in the U.S. alone, according to financial intelligence firm Refinitiv.

While that's down from last year's record--when worldwide deals measured $2.5 trillion midyear--the first half of the year still ranks as the third most active since 1980, when records began.

What's more, the next 12 months are likely to be even more active. Deloitte's 2019 M&A survey report shows 79 percent of respondents expect to close more deals in the next 12 months, up from 70 percent of respondents who expected as much last year.

Check out the most notable startup acquisitions of the year, listed by deal announcement date.

1. Ultimate Software Fetches Ultimate Price

The Weston, Florida-based HR software firm Ultimate Software made major headlines this February when San Francisco private equity firm Hellman & Friedman scooped it up for $11 billion. While private equity gets a bad rap for unraveling and selling off parts of struggling companies, Ultimate Software says that isn't true in this case. The company plans to reinvest in products and services as well as reward employees. During its two-decades in the public markets, Ultimate grew to well over $1 billion in annual revenue and $65 million in profit. Its clients include fast-food chain Subway and hotel chain Red Roof Inn.

2. Facebook Snaps Up Visual Shopping App 

Back in March of 2018, GrokStyle helped Ikea give shoppers a new way to browse: Instead of meandering around a warehouse, they could use an app to visualize furniture in digital versions of their homes. Then, in February, Facebook snapped up the San Francisco-based A.I. shopping app for an undisclosed sum. While it's still unknown how the social network will use the visualization technology, it's not hard to imagine Instagram and GrokStyle coming together to offer a digital way to window-shop.

3. Amazon Taps Mesh Router Company

Amazon's smart devices already may have found their way inside your home. Now the company wants to operate your router, too. In February, the e-commerce giant snapped up San Francisco's Eero, which makes a whole-home mesh Wi-Fi system, for what many in the industry called a fire sale. While the initial terms for the deal weren't disclosed, it was later reported to have been worth $97 million. The startup had raised close to $100 million in venture capital from investors including Index Ventures and Menlo Ventures, and it had at one point been valued at as much as $251 million. All the same, Alexa's quest to become the one voice to rule them all just scored a point.

4. Harry's Goes Corporate 

The men's grooming industry has seen a string of acquisitions in the past couple of years--most recently the sale of Harry's for $1.37 billion in May. With that deal, the startup, co-founded by Jeffrey Raider and Andy Katz-Mayfield, joined Edgewell Personal Care's brands, which include Schick and Hawaiian Tropic. At the time of the deal, Raider and Katz-Mayfield were expected to take over the company's U.S. operations.

5. Twitter Ups Its A.I. Expertise 

Like many social media sites these days, Twitter has a fake news problem. In June, the company announced it bought the London-based fake news detection software maker Fabula AI to help. Founded in 2018, Fabula's patented A.I. system, dubbed "geometric deep learning," contains algorithms that learn from massive data sets gleaned from social networks. Twitter, which did not disclose the terms of the deal, said at the time that Fabula will help the company strengthen its machine learning expertise. 

6. Google Bolsters Cloud Business With Looker 

Also in June, Google parent company Alphabet paid $2.6 billion for Looker, an analytics startup that helps businesses understand their customer, employee, and competitor data. Google explained at the time that it snapped up the Santa Cruz, California-based startup to help buttress its own Google Cloud offerings. According to Bloomberg Businessweek, the move could help the search giant better compete with rivals Amazon and Microsoft. Looker, which was founded by former software engineer Lloyd Tabb, had raised $280 million in venture capital since it launched in 2012.

7. Salesforce Gets Visual

Salesforce wanted a piece of Tableau's data analytics platform--and it was willing to pay a premium for it. In June, the San Francisco tech giant purchased Seattle's Tableau in an all-stock deal valued at $15.7 billion. Founded in 2003, Tableau helps companies create data visualizations--graphs, maps, and the like. The deal was viewed by analysts as critical for Salesforce, which has faced increasing competitive pressures from Microsoft and Adobe in recent years. Tableau had ranked five times on Inc.'s list of the fastest-growing private U.S. companies.

8. Grove Collaborative Gets Reinforcements 

San Francisco's Grove Collaborative booked $104 million in 2018 by selling sustainably produced, well-designed products online. However, it wanted reinforcements when it came to building out a women's health product line. Grove co-founder Stuart Landesberg for months tapped Sustain Natural founder Meika Hollender for advice before paying an undisclosed sum for her sexual health company. Under Hollender, who is expected to join Grove's leadership team out west, the New York City-based company has embraced edgy, feminist marketing since its inception in 2013. 

9. Facebook Finds a New Way to Connect 

Facebook's augmented and virtual reality lead Andrew Bosworth announced in September that the social networking company would acquire the New York City-based neural networking startup CTRL-Labs. While the deal amount was undisclosed, Bloomberg estimated the value to be between $500 million and $1 billion. Founded by neuroscientists Thomas Reardon and Patrick Kaifosh, the company's primary offering includes smart wristbands that can transmit electrical signals from the brain to a computer. The goal is to help humans communicate with computers using brain signals; it's unclear how exactly Facebook might deploy the tech.

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