Startups are trading their hoodies for ties.

A new generation of tech upstarts is appealing to big banks with financially-focused apps, software and systems. They’re cashing in as the industry looks to adapt to a new digital and regulatory environment.

Startups in the financial technology field, or “fintech” as it’s commonly called, are booming, and big institutions such as Bank of America BA , Citibank C and American Express AMEX are pouring money into these nimble new companies to meet modern regulatory, digital and security challenges.

Venture investment in global fintech tripled between 2008 and 2013 to $2.97 billion and is expected to reach $8 billion by 2018. Money put towards these ventures has also increased at more than four times the rate of overall VC investment over the past three years, according to a study by Accenture ACN .

“We owe it to ourselves, our customers, our clients and our shareholders to cast a wide net and find new ways to solve existing and new challenges,” said David Reilly, a technology infrastructure executive at Bank of America. “Engaging with the start-up and venture capital community forces us to think about innovation in a different way, more revolution than evolution.”

Major U.S. banks, along with global players such as Banco Bilbao Vizcaya Argentaria BBVA and HSBC HSEB , have developed in-house venture capital funds that invest directly in budding technology companies. The size of these funds can range anywhere from $50 million to $250 million. By investing early, banks gain early access to innovative solutions that can help reduce information technology costs and make their businesses more flexible to consumer needs, said Reilly.

“As entrepreneurial costs go down, more and more institutions are focusing on how venture innovations can help them be more competitive and efficient,” said Bob Gach, a global managing director at Accenture who co-authored the study with the Partnership Fund for New York City. “This is why many financial services companies are ramping up accelerators and innovation labs, and sometimes investing in fintech ventures directly.”

Many institutions are choosing to start their own labs, or partner with existing incubators, such as the FinTech Innovation Lab, which was co-founded by Accenture and the Partnership Fund for New York City and whose fourth demo day event in New York is Thursday. Fintech Innovation Lab is supported by 15 major corporations and has expanded to London and Hong Kong, where fintech startup activity is just now starting to pick up, said Gach.

Bank of America has supported all three Fintech Innovation Lab programs and also holds its own technology innovation summit on the West Coast annually. While the bank values its investments in startups, it carefully considers when to build versus buying or partnering.

“In many cases, where building won’t provide a competitive advantage, our choice is to buy; where differentiation matters, we explore whether building makes sense,” said Reilly. “Casting a wide net and opening ourselves up to a variety of solutions is the best model to serve our customers and clients.”