Eric Rosenbaum for CNBC:  The market has been positioned somewhere between awe and incredulity as new blockchain exchange-traded funds have attracted more than $200 million from investors in little more than a week of January, but it's a robot ETF that is blowing away the competition among trendy tech investments over the month.

The Global X Robotics and Artificial Intelligence Thematic ETF (BOTZ) has taken in more than $650 million from investors in January — $659 million as of the end of the week of January 26, to be exact. That's an asset-gathering pace that would be good for most broadly diversified equity funds.

It's not entirely surprising given the performance from BOTZ — up more than 15 percent in the past month and a return of more than 66 percent in the past year — though the January surge in assets is sizable and points to several investing trends that may be transitioning from niche to needing to be taken seriously.

"Six hundred fifty million dollars in a month is a lot for a thematic ETF. ... But thematic ETFs are gaining acceptance, particularly since some of them have delivered excellent performance of late," said Neena Mishra, director of ETF Research at Zacks Investment Research.  Full Article: