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If Adam Nash had his way, your money would be managed by robots.

As CEO of Wealthfront, Nash is in charge of 100 people who manage an army of computers that are constantly crunching algorithms designed to buy, sell and track more than $2 billion worth of stocks and bonds.

"Computers are completely rational, and they have nothing else to do," said the 40-year-old CEO. "This service in the cloud will watch your account 24/7 and do all the small things you should have been doing with your money but you and I don't have the temperament or the time to do."

So far, people like his pitch. This year, the amount of money managed by Wealthfront's robo-advisers has grown by 52 percent, or $900 million. The Palo Alto, California-based firm, founded in 2011, now manages $2.6 billion in assets.

Wealthfront is part of an emerging group of startups asking people to put the fate of their money in the hands of computers. Along with other Silicon Valley-backed startups such as Betterment and Personal Capital, Wealthfront says its software can manage money better and at a lower cost than emotional, irrational humans.

These startups are now handling a combined $6.7 billion in assets.

The computers have held their own for some investors. "Our performance has met our expectations," a spokesman for Personal Capital said via email.

Wealthfront said the "average client" can expect in the long run a return of 5.85 percent before taxes. By comparison, the average return on the S&P 500, one of the most widely used benchmarks of the stock market, was 7.6 percent between 2005 and 2014.

Robo-Buffett or the HAL of finance?

To get a sense of how much Silicon Valley thinks robo-advisers can change Wall Street, you have to follow the money.

Venture capitalists are already convinced this is one of the next big consumer trends. They've invested $623 million in computerized-investment startups since 2008, according to venture research firm Tracxn. More than two-thirds of that amount, $439 million, came in the last year and half.

Such funding birthed 18 companies last year and 11 so far this year. These companies offer a range of financial services. Startups like Acorns have a mobile app that will auto-invest spare change after a purchase. Others, like FutureAdvisor and SigFig, monitor investment accounts and recommend changes to your portfolio.

Then there are Wealthfront, Betterment and Personal Capital, all of which tout automated investment services. (Personal Capital considers itself a hybrid because it combines automated tools with humans advisers.) And the venture community is lining up: Each company has raised more than $100 million over the last few years.

Why so much attention?

Matt Harris of Bain Capital Ventures, which has backed SigFig, said investment advisers who work with most people (think anyone who's not the super rich) typically aren't pulling in the best returns.

"Your adviser is probably not a genius," Harris said. "Unless Warren Buffett is managing your money, you're way better off doing a similar algorithmic approach."

"You're only as good as your code, and right now the code isn't writing itself." Christopher Geczy of the Wharton School

Harris and his peers argue that computers are able to offer to the masses the sophisticated investment strategies once reserved for the ultra-rich. Because the companies don't have to pay employees for their work, they can charge customers less.

Even if computers can't do much better than humans, customers still win out, said John Jarve of Menlo Ventures, which has backed Betterment. The average person will "get a higher rate of return on their investments because the fees they're charged will be less," he said.

Someone whose money is managed by a traditional investor will pay more than 1 percent a year in fees, while automated investors such as Betterment and Wealthfront charge about a quarter of that, according to technology research firm Forrester Research. Wealthfront charges nothing for customers with less than $10,000 invested.

Let go, let bot

If a future of computers handling your nest egg freaks you out, then start building a time machine and return to the past. Even old-school investment services such as Charles Schwab and Vanguard have launched robo-investment services.

"Robo-advisers are here to stay," said Christopher Geczy, a professor at the Wharton School of the University of Pennsylvania, where he teaches wealth management.

Still, Geczy sees reasons for humility among Silicon Valley's Wall Street upstarts.

"You're only as good as your code, and right now the code isn't writing itself," he said. "If it were so easy, Silicon Valley would be running hedge funds."

Update, 4:26 p.m. PT: Clarifies Personal Capital's hybrid human-robo model.