受调查的公司是Ellevest、Sigfig、 Wealthsimple、 Betterment、Easyvest、Investify、Growney、Yomoni、Whitebox、Quirion、Vaamo、Indexa Capital、Moneyfarm、Scalable Capital和 Nutmeg.
European robo advisers have been severely criticised in a report which found fees obscured as well as "inexplicable" portfolio and performance differences.
The mystery shopper survey by Better Finance targeted robo players that have entered the market in the past 10 years and are not connected to established providers.
Platforms surveyed included 11 platforms from seven different EU countries and four US platforms and one Canadian.
Fees - Mifid breach
Analysts said the way some robo advisers presented their performance data was misleading and in breach of regulations.
"The reliance on past performance data in the estimate of future performance scenarios is unfortunate," the report states.
"In addition to being inherently misleading, Mifid II clearly states that: '…such forecasts are not a reliable indicator of future performance'.
"For this reason, a clear warning of this unreliability is required by EU secondary legislation to accompany future performance forecasts. Such warnings are unfortunately missing from a majority of the robo advice platforms included in this study."
The authors said they "strongly disagreed" with the use of future performance scenarios, and found "the inclusion of the past performance of a proposed portfolio, or of a comparable fund, to be far more useful, enabling the potential investor to take informed decisions."
According to the researchers, half of the platforms did not present information on fees when presenting final investment advice (four out of five in the US and four out of 11 in Europe), and only 31% explicitly state that final returns include fees.
The remaining 69% of platforms did not limit themselves to presenting gross returns, but simply did not specify whether fees were included in the calculation of future performance.
"The information on fees disclosed on the websites is often confusing or even misleading and often accessible only after some digging into the more obscure corners of the website," it reads.
"However, this is not the case for all robo advisors, since detailed information on fee allocation, can easily be found on platforms such as Nutmeg, Yomoni, Growney and Investify.
Performance forecast and asset mix divergence
The research team expected fewer differences between the platforms considering the short horizons given by the mystery shoppers - a fictitious millennial and a baby boomer.
The differences in terms of returns on investment between the different platforms (or how much the investor would make on top of his initial €/$/?10,000) are significant, starting from €880 (?776, $1,026) (Ellevest) and reaching up to €8,300 (Wealthsimple).
The research team could find no explanation as to how such huge differences (almost 1,000%) in expected outcomes could exist.
Similarly, researchers could find no explicable reason for the difference in equity allocation ranging from 32% to 89% in equity ETFs.
The most important element the research team observed is that there was a clear disassociation between the equity allocation in the portfolio and the expected investment gain for the investor.
Researchers said this made them "highly misleading" for investors.
According to the CISI, the survey highlighted the need for client education.
Commenting on the study, Jacqueline Lockie, CISI head of financial planning, said: "Clients with the same situation and risk appetite saw costs vary widely even where the portfolios recommended very similar and composed mostly of ETFs.
"The same client research showed wide variation in equity allocation which varied from 20-80% equity asset allocation with same client profile.
"Therefore anything we can do as financial planning professionals to look at ways of improving investor education both in financial planning and robo advice as well as simplifying the way products and investments work to aid better understanding for all alongside sharing share best practice is to be applauded."
Better Finance is an association of national member organisations aimed at improving financial services in Europe and strengthening consumer rights.
The firms surveyed were Ellevest, Sigfig, Wealthsimple, Betterment, Easyvest, Investify, Growney, Yomoni, Whitebox, Quirion, Vaamo, Indexa Capital, Moneyfarm, Scalable Capital and Nutmeg.