The robots are rolling forward with a full-frontal assault to capture Wall Street’s vast investment fees and commissions.

More investors are warming to the cold, steely embrace of the increasingly sophisticated, low-cost automated robo-advisers. The primary reason is to save money on those fees and charges.

Bots are squeezing their flesh-and-blood competition and threatening the jobs of thousands of human brokers in the $20 trillion US wealth management business.

Nearly one in three investors says these machines are superior at picking stocks and lessen their risk, and almost as many say the machines are better at selecting investments for retirement than human brokers, according to a new study of US investors by market research and consulting firm Spectrem Group.

Respondents had a minimum net worth of $100,000. An earlier study by Spectrem in 2015 was not as bullish, with 6 percent of affluent investors saying they’d used a pure technology-based platform to enter information for a robo-recommended portfolio.

Today, more US investors are pulling assets from human wealth managers and putting the money quietly to work with the expanding army of robo-advisers.

Spectrem says rookie investors — many of them millennials — are more often using robo-advisers than human ones.

Masood Vojdani, chief executive of Bethesda, Md.-based MV Financial, a wealth management firm with more than $500 million in assets under management, is not surprised. “Robo-advisers could be important for younger investors by allowing them to start investing earlier in their lives than a few years ago, which is incredibly valuable,” Vojdani told The Post, despite his mixed feelings about robos.

Robo-advisory, less than a decade old, may expand much faster than experts originally forecast. Consultancy A.T. Kearney earlier estimated that by 2020, robo-advisers will manage $2 trillion in the US, or roughly 5.6 percent of the country’s investment assets, up from 0.5 percent about 12 months ago.

The trend has sent the traditional wirehouses and brokers scrambling.

“Clearly, the pressure that rests on wealth management firms to trim the costs involved in manufacturing and distributing portfolios, paired with continuing fee pressure [will continue the firms to move toward robo advising],” said Isabella Fonseca, an Aite Group analyst who covers wealth management.

Entrenched players, like Vanguard and Charles Schwab, have already taken these defensive measures, offering low-fee automated plans alongside their human-broker services to attract young millennials, a move that draws guffaws from one stand-alone upstart as they begin to hire sales staff from the old guard firms.

“We’re hiring from the competition at Fidelity, Vanguard and Schwab, and training some of our own experts,” said Jon Stein, CEO of New York-based Betterment, the largest independent robo-adviser, with $7 billion in assets under management and a staff of 220.

The robo space also includes upstarts like Acorns and Wealthfront.