Wall Street plans to spend nearly half its IT budget on the public cloud in 2020. Here's where firms see the biggest benefits, and what's still holding them back.

• Investment by Wall Street into the public cloud will account for roughly 48% of tech budgets in 2020, according to a recent survey from Refinitiv.
• The survey indicates banks, hedge funds, and asset managers are putting an increasing amount of resources into moving to the public cloud.
• However, impediments towards more adoption still remain, as nearly all of those surveyed said they feel their firms are limiting their use of the public cloud due to regulatory concerns.
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Wall Street's great migration to the public cloud is in full swing.

Senior technologists at banks, hedge funds, and asset managers said they plan to spend nearly half their tech budgets on the public cloud in 2020. That's according to a recent survey regarding public cloud adoption conducted by Refinitiv and shared with Business Insider of 300 C-level and senior technologists at a wide range of financial firms.

Public cloud investment will make up roughly 48% of firm's IT budgets, indicating Wall Street's intention to continue to put more resources into the tech. That's up from 41% of tech budgets this year, according to the survey, and only 34% of budgets in 2018.

Wall Street has good reason to increase the time and money spent on moving off physical servers and out of local databases and onto the public cloud.

For starters, financial firms have seen big savings from making the switch. For those who completed public cloud projects, 76% of respondents said doing so led to immediate cost reductions that were "better than expected."

Read more: Wall Street is finally willing to go to Amazon's, Google's, or Microsoft's cloud, but nobody can agree on the best way to do it: 'If you pick a favorite and you're wrong, you're fired'

But moving to the public cloud isn't just about saving money. Taking tools and data "off premise" - out of physical servers - allows firms to innovate and experiment faster and cheaper than before. More than half the respondents said public cloud projects they completed allowed them to accelerate their time to market and lower their cost of experimentation "better than expected."

The ability to innovate quickly is a major consideration of big banks in particular, as they look to fend off smaller, more agile startups that continue to creep into the space.

However, for all the benefits the public cloud offers firms, there are still issues holding them back. One of the biggest is uncertainty around regulatory requirements. Only 6% of respondents said their organizations weren't limiting the use of the public cloud in some way because of regulatory concerns.

Some said regulators requiring certain data to stay put on physical servers limited them, while others pointed to rules around having to use multiple public cloud providers for resiliency purposes, which some banks have struggled to do.

But where regulators are proving most difficult is in their lack of consistency, respondents said. Rules differ across jurisdictions, making it tough for a firm to create a global public cloud program.

See more: Bank of America is putting the finishing touches on a 7-year cloud journey its CTO says has saved the bank billions and improved customer interactions

A majority of respondents also cited short-term targets, pointing to the potential impact the new tech would have on revenue, as another barrier to investing more into the public cloud. Concerns over compatibility with security tools was also a commonly cited reason by respondents for limiting further investment.

Security in the public cloud is one of the biggest reasons Wall Street firms have pointed to in the past as a reason they've resisted moving off physical servers.

"Larger clients have not necessarily seen the greatest improvements from cloud in the security area," said Gavin Carey, head of enterprise in EMEA at Refinitiv, in the report.