A robotics-related exchange traded fund has maintained its outperformance and remains a popular investment play in the new year.

The Global X Robotics & Artificial Intelligence Thematic ETF (NasdaqGM: BOTZ) jumped 15.1% year-to-date and surged 66.5% over the past year.

The outperformance has drawn a lot of attention among ETF investors, with BOTZ attracting $659 million in net inflows as of the end of last week, CNBC reports. The Global X Robotics & Artificial Intelligence Thematic ETF now holds $2.4 billion in assets under management.

“it’s hard to say I’m not a little surprised,” Jay Jacobs, director of research at Global X Funds, told CNBC. “We obviously believe a lot in this fund, and the amount of money moving into ETFs this month is truly staggering.”

“Demand has been strong for thematic ETFs in recent months, and BOTZ in particular had a strong return in 2017,” Todd Rosenbluth, director of ETF & mutual fund research at CFRA, told CNBC.

BOTZ provides exposure to companies involved in the adoption and utilization of robotics and artificial intelligence (AI), including those involved with industrial manufacturing, medicine, autonomous vehicles, and other applications. The thematic sector ETF helps investors gain targeted exposure to a quickly growing segment of the tech industry.

“BOTZ offers investors access to a rapidly emerging technological theme of the application of robotics and artificial intelligence around the globe,” according to Global X. “The robotics industry is expected to grow 10% per year, eclipsing $80 billion in market size by 2020. The AI market is expected to reach $5.1 billion by 2020, from just $420 million in 2014.

Millennials may be a huge driving factor in the increased interest for thematic ETF plays, like BOTZ. Jacobs pointed out that in past survey works, millennials exhibited far greater interest in thematic investing than members of Gen X and baby boomers. A little over 80% of millennials said they were “very” or “extremely” interested in thematic investing in a survey. “Millennials are thinking 20 years ahead,” Jacobs said.

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