In another year of astronomical asset growth for the exchange traded funds industry, some unique, highly focused ETFs are adding assets at feverish paces. That includes the ROBO Global Robotics & Automation Index ETF (NASDAQ: ROBO), the original exchange traded fund dedicated to robotics investing.

Just over two months ago, ROBO eclipsed the $1 billion in assets under management. Now, ROBO is celebrating its fourth anniversary and is doing so with over $1.5 billion in assets under management. Said another way, ROBO grew by about 50% in barely more than two months.

The ETF tracks “the ROBO Global Robotics & Automation Index, “which is the brainchild of a team deeply entrenched in the robotics industry who created the innovative methodology,” according to Dallas-based ROBO Global. “The index and subsequent ETF offer investors access to the entire value chain of robotics, automation and artificial intelligence. The ROBO Global Robotics & Automation Index is comprised of 83 global companies from 14 countries in North America, Europe, Asia and the Middle East and offers almost no overlap with traditional equity indices.”

The robotics ETF’s portfolio may also provide exposure to companies with sustainable growth opportunities, as the underlying ROBO Global Robotics & Automation Index has exhibited attractive sales growth, EBITDA growth and earnings-per-share growth. The underlying index has even outperformed the broader technology and S&P 500 index since the 2008 financial downturn.

“Comprised of 85 securities that span 14 countries, the fund invests in the robotics, automation and artificial intelligence (RAAI) sector, as defined by the ROBO Global Robotics & Automation Index. A team of financial and robotics experts, including five Ph.D.s, constructed the Index that the ROBO ETF track,” according to a statement from Dallas-based ROBO Global.

Related: The Growth Potential of the Robotics ETF

Robotics- or automation-related products and services include any technology, service or device that supports, aids or contributes to any type of robot, robotic action or automation system process, software or management.

The once-far flung concept of robotics is gaining some momentum. For example, the International Federation of Robotics expects that worldwide sales of robots will rise by 6 percent between 2014 and 2016, and over 190,000 industrial robots were supplied to companies around the globe in 2016.

ROBO’s “index is comprised of more than 80 rapidly developing companies spanning more than 14 countries that are categorized into 12 subsectors.” The index is licensed across four continents.

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