Banks are watching wealthy clients flirt with robo-advisors, and that’s one reason the lenders are racing to release their own versions of the automated investing technology this year, according to a consultant.

Millennials and small investors aren’t the only ones using robo-advisors, a group that includes pioneers Wealthfront Inc. and Betterment LLC and services provided by mutual-fund giants, said Kendra Thompson, an Accenture Plc managing director. At Charles Schwab Corp., about 15 percent of those in automated portfolios have at least $1 million at the company.

“It’s real money moving,” Thompson said in an interview. “You’re seeing experimentation from people with much larger portfolios, where they’re taking a portion of their money and putting them in these offerings to try them out.”

Traditional brokerages including Morgan Stanley, Bank of America Corp. and Wells Fargo & Co. are under pressure to justify the fees they charge as the low-cost services gain acceptance. The banks, which collectively employ about 46,000 human advisors, will respond by developing tools based on artificial intelligence for their employees, as well as self- service channels for customers, Thompson said.

“Now that they’re starting to see the money move, it’s not taking very long for them to connect the dots and say, ‘Whatever I offer for a fee better be better than what they’re offering for almost nothing,”’ Thompson said. Technology will “make advisors look smarter, better, stronger and more on top of the ball.”

Keeping Humans

Robo-advisors, which use computer programs to provide investment advice online, typically charge less than half the fees of traditional brokerages, which cost at least 1 percent of assets under management. The newer services will surge, managing as much as $2.2 trillion by 2020, according to consulting firm A.T. Kearney.

More than half of Betterment’s $3.3 billion of assets under management comes from people with more than $100,000 at the firm, according to spokeswoman Arielle Sobel.

Wealthfront has more than a third of its almost $3 billion in assets in accounts requiring at least $100,000, said spokeswoman Kate Wauck.

Schwab, one of the first established investment firms to produce an automated product, attracted $5.3 billion to its offering in its first nine months, according to spokesman Michael Cianfrocca.