A TOP EXECUTIVE at a major Wall Street bank is deep into his spiel on how artificial intelligence will make the firm smarter and leaner when he pauses to take a question: What does this mean for young people entering the business?

The silence grows.

鈥淚t鈥檚, um,鈥 he says, shifting tone and making clear he can鈥檛 speak publicly. That question is gnawing at him, he confides, because he has kids. 鈥淚 would want them to pick their careers very carefully. I think AI is going to eliminate most jobs. That鈥檚 a private view. I think we鈥檙e just starting to feel that.鈥

Within the upper echelons of many financial firms, there鈥檚 a lot of soul searching as executives prepare to roll out a new generation of technology. Publicly, they鈥檙e upbeat, predicting machines will perform almost all repetitive tasks, freeing humans to focus on more valuable pursuits. Privately, many confide to peers, consultants and sometimes journalists that they鈥檙e worried about what will happen to their staffs 鈥 and what to tell them.

There鈥檚 also uncertainty. Maybe it鈥檚 all overblown, executives say, because the tech will be hard to implement and humans will find new roles. Or perhaps it鈥檚 the beginning of the end for legions of professionals in one of the world鈥檚 most lucrative fields. Can jobs held by office-dwelling millionaires disappear like those on factory floors?

The result, is that employees aren鈥檛 getting a clear message on what鈥檚 to come.

For a rosy scenario, look to McKinsey & Co. In July, the consulting firm published a report estimating machines are ready to assume roughly a third of the work now performed by banks鈥 rank and file. The authors framed it as positive: People will have more time to tend to clients, conduct research or brainstorm ideas. So far, it noted, firms at the forefront aren鈥檛 slashing jobs.

At JPMorgan Chase & Co., one of the most tech-savvy banks, Chief Executive Officer Jamie Dimon predicted in June that his work force will more likely grow than shrink over the next 20 years. Technology may displace workers, he鈥檚 said, but it also creates opportunities.

Yet in interviews, about a dozen Wall Street executives and consultants responsible for deploying technologies 鈥 and steeped in their capabilities 鈥 were more bearish on humans. Machines will take over task after task, they said, and banks simply won鈥檛 need nearly as many people.

It鈥檚 time for senior managers to stop sugarcoating, said Simon Moss, who has been advising banks and investing firms as head of Grant Thornton LLP鈥檚 fintech and innovation practice for the industry.

鈥淎re there positions in financial services that are actually untouchable from technology? The simple answer is 鈥楴o,鈥欌 Moss said. 鈥淚t鈥檚 just a case of when.鈥

Early adopters like JPMorgan, Goldman Sachs Group, Inc. and Bank of New York Mellon Corp. are experimenting, he said. They鈥檙e working with tech including machine-learning software that improves itself by searching data for patterns, and natural-language processing, which helps computers comprehend human speech. Once firms figure out how to deploy those, rivals may quickly follow suit. Humans will have less to do, and banks will whittle costs by shrinking headcount.

鈥淪itting with excess capacity is not a good business decision,鈥欌 Moss said. Managers should start warning employees that they need to learn more skills to stay on.

That鈥檚 supported by history. Floor traders who once shouted orders in raucous marble-columned exchanges have seen their numbers dwindle since the 1990s, forcing many to seek new work. Gary Cohn, who last year stepped down as president of Goldman Sachs, told investors in 2011 that technology had helped the firm slash equities staff by more than half over the previous decade. The trend was similar in currencies.

Few automators set out to kill jobs.

Inder Thukral, cofounder of Kognetics LLC, is making machine-learning algorithms that ease life for investment bankers working around the clock on mergers and acquisitions.

鈥淚t鈥檚 the spirit-crushing work that it鈥檚 replacing,鈥 he said in an interview. Dealmakers should focus on only the most important stuff, he said. 鈥淪earching through 6,000 documents is a computer鈥檚 job, so let it do it.鈥

Ultimately, that means fewer people will be needed, he said. But if planned well, banks may be able to avoid firings through attrition 鈥 leaving positions open as they become vacant.

That hope comes up a lot. At UBS Group AG executives are using a digital employee known as Amelia to quickly perform repetitive tasks in the firm鈥檚 investment bank and asset management divisions. Executives say employees shouldn鈥檛 fret as the software, developed by digital labor company IPSoft, Inc., spreads across operations.

鈥淭he first question at mind is 鈥榃hat happens to my job?鈥欌 said Tom DeCarlo, a managing director who sits on the bank鈥檚 innovation committee. But dismissals aren鈥檛 his plan. 鈥淎s we have attrition 鈥 internal or external 鈥 I鈥檓 just not replacing those people.鈥欌

Sergio Ermotti, the bank鈥檚 CEO, said in a recent interview that the firm could shed 30% of its employees over a decade. Another senior UBS executive, asking not to be quoted by name, estimated technology would allow it to operate with up to 40% fewer people in just four to eight years.

Attrition has limits. Some employees may retire, while others quit to take more promising jobs elsewhere. But if the whole industry is shrinking, those opportunities may be scarce.

There鈥檚 no denying that fewer people will be needed, according to Richard Johnson, vice-president of market structure and technology at Greenwich Associates. At least, he said, the transformation will be incremental. 鈥淚t鈥檚 not as if everyone is going to come to work and there鈥檚 a bunch of robots sitting in their seats.鈥

But eventually, a transformation is coming, said IPSoft CEO Chetan Dube, who鈥檚 working with UBS and more than 100 other finance firms to deploy his company鈥檚 software.

鈥淭ime, tide and technology will wait for no one,鈥 he said. 鈥淲e鈥檝e tippy-toed around this topic too much and for too long.鈥 鈥 Bloomberg