The pay-as-you-go model of SaaS — software as a service — has certainly gained traction in the world of banking.

SaaS has helped banks and other traditional financial institutions to take advantage of apps or software offered (commonly) by fintechs, without having to buy or build out the technology.

But as fintechs are getting bigger, and banks are getting more tech-savvy, can the roles switch? In other words, are banks ready to sell their own tech solutions to fintechs that are seeking scale?

BaaS can be a “huge opportunity” for banks, as far as they find a niche “differentiator,” according to Kaushalya Somasundaram, head of fintech partnerships and strategy at HSBC.

“For example, we [HSBC] are the number one trade bank, and we have a huge amount of marketshare there, some other banks have built out extensive robo advisory solutions,” she said at a panel during Empire Startups Fintech Conference today. “Niche propositions like that are certainly areas that [banks] can capitalize on by building a platform as a service.”

Being able to differentiate will be the key factor for banks seeking to offer such services, according to Kristi Ross, co-CEO of a trading platform tastytrade. “Being able to have BaaS is incredibly positive,” she said. “It has to be a niche area, but it would be a great way for banks to create that extra revenue stream.”

The trend, however, hasn’t gained much traction across the large FIs yet, partly due to regulatory concerns around open banking.

“It’s going to be a while before banks are able to adopt this model, there are a number of important implications that have to be considered first,” Luis Valdich, managing director at Citi Ventures, said during the panel. “There are also more traditional infrastructure players that are better geared to sell those solutions to third parties.”

FIs in Europe face a different regulatory landscape, and have, as a result, been more successful in providing banking as a service to fintechs. A German startup solarisBank, for example, received a banking license last year, allowing it to freely offer financial solutions– such as compliance solutions or capital financing– to fintechs.

There are, however, several examples of U.S. banks that are exploring the BaaS model, according to Valdich. Those are mainly tech-driven, smaller-scale banks, such as Cross River Bank or Web Bank, he added.