(Bloomberg) -- How big a threat are the new batch of robo-advisors to traditional active fundmanagers?

Are they, as Sanford C. Bernstein & Co LLC put it in a newresearch note, an "innocuous robot like R2-D2 or are theyTerminator?"

To answer the question, Bernstein analysts openedmultiple accounts at two prominent European-based robo-advisors, Nutmeg Saving and InvestmentLtd. and MoneyFarm SIM SpA.

While they came away impressed with the accounts — one high-riskmodel portfolio was forecast to deliver at least 6 percent per yearnet of fees — they find it hard to believe that big industryincumbents won't break through what they see as low-barriersto entry for a growing industry.

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Robo-advisors, which feature relatively low fees andan investing-on-autopilot approach, have so far beenexpanding as investors shift towards passive managementstrategies rather than active management which has been tarnishedby a stigma of high commissions and lacklusterperformance.

"The robo-advice approach looks to have a rosy future, thoughnot necessarily the current robo-advisors themselves," theteam, led by Inigo Fraser-Jenkins, write in the note."Barriers to entry for the actual robo part are very low we think.So this may well be exploited by more established finance (ortech) brands with a broad distribution capability," theywrite, adding that a number of large asset managerslike Vanguard Group, Northwestern Mutual Co.and Charles Schwab Co. have already jumped into the space.

Tech giants Alphabet Inc. and Facebook Inc. have alsotaken a look at the asset management industry in recentyears.

The largest robo-advisors in the U.S. had roughly $60billion in total assets under management as of September 2016,according to Bernstein's estimates.

While still a small piece of the nearly $70 trillion assetmanagement industry, a forecast by McKinsey & Co. expectsthe funds managed by robos to grow substantially in the futurewith the potential to encompass $13.5 trillion worth ofassets if more affluent households start to move largerportions of their assets into the passive strategies atrobos.

Robo-advisors "are more R2-D2 given they currently account foronly a very small portion of invested assets,"Bernstein concludes. "The most immediate issue caused by therobot advisors is that in their current form they accelerate thealready relentless shift to passive investments and thus putadditional pressure for those active funds to have substantiallylower fees to make them competitive."

If that pressure continues to grow then the robots could belooking a lot less cuddly to active fund managers.

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