Some niche exchange traded funds (ETFs) push the boundaries of far-flung concepts, including ETFs that hold robot stocks.

The theme is still nascent when it comes to investing in robotics, which deals with the design, operation and use of robots. But white, blue and no collar jobs all over the world are becoming increasingly automated, so the idea of betting your money on robots is not far flung.

Some of the world's largest economies are rapidly adopting robots. “Roughly three-quarters of all robots are sold in five countries: China, South Korea, Japan, the U.S., and Germany, according to the International Federation of Robotics, a trade group,” reports Barron's.

Investors can find a long list of robots stocks to buy to play this trend. (See also: Why Robots Will Rise In the Age of Trump.)

For those who prefer funds, we describe two dedicated robot ETFs below.  

Robo Global Robotics & Automation Index ETF (ROBO)

The Robo Global Robotics & Automation Index ETF is the oldest robotics ETF, having debuted in October 2013. ROBO follows the Robo-Stox Global Robotics and Automation Index and holds 85 stocks.

The investment thesis for ROBO is not dependent on developed economies. Sales of robots in China grew 50% over the past several years, and nearly half of all robots sold have been to factories in Asia since 2009, according to research firm Robo Global.

ROBO has returned 26% since coming to market. Even with an annual fee of 0.85%, which is high compared to most ETFs, ROBO has over $284 million in assets under management.

Global X Robotics & Artificial Intelligence Thematic ETF (BOTZ)

The Global X Robotics & Artificial Intelligence Thematic ETF is just seven months old and tracks the Indxx Global Robotics & Artificial Intelligence Thematic Index. BOTZ holds 28 stocks, nearly 70% of which are Japanese or American companies.

Over 30% of BOTZ member firms are industrial machinery firms while another third are electronic equipment makers, electronic components manufacturers or healthcare equipment producers.

BOTZ is up 12.3% since debuting and is cheaper than ROBO with an annual expense ratio of 0.68%. Thus far, investors have allocated $21.5 million to BOTZ.