There's a growing fear that investor valuations of fintech firms may have run ahead of company fundamentals, according to industry experts.

Panelists at a Goldman Sachs tech event said this week that investors are starting to question whether valuations of fintech (financial technology) companies are stretched after money poured into the sector in 2015.

Private investment into fintech has rocketed in the last two years, with over $32bn worth of investment in the sector 2014-15, according to a recent stats from broker Peel Hunt.

While the majority of this investment has been in the US, UK fintech is also growing fast and it is one of three sectors forecast by the CBI to contribute £300bn to the economy by 2020.

Banks, meanwhile, are starting to realise the full potential of digital technologies and their potential to disrupt and transform the banking industry.

Barclays and Santander have started investing in fintech companies through in-house venture capital funds.

This week private equity arms of Standard Chartered and Goldman Sachs invested a combined $28m in Vietnamese startup M_Service, the operator of mobile e-wallet MoMo.

But experts at Goldman’s first ever 'Disruptive Technology' forum warned that fintech companies themselves will start to face increasing challenges, particularly when it comes to explaining their valuations, business propositions and user benefits to potential customers.

"There was a large focus on the next staging post for mass consumer adoption of FinTech products and services, while a number of players believe increasing regulation, as businesses scale, will create growing barriers to entry," said Goldman's own summary of the panel discussion.

“A key milestone may be when fintech services are simply called ‘finance’, signalling an improvement in mass market public perception and understanding,” the firm added.

Panelists included Christian Faes, co-founder and chief executive of peer-to-peer lending platform LendInvest and Magnus Nilsson, founder and chief operating officer of mobile payments firm iZettle.

Funding approaches were also discussed, with retail deposits, bank funding lines and institutional invested capital highlighted.

All broadly agreed that diversification of funding sources is important especially in a downturn, panelists also cited their preferences for certain funding sources dependent on their business models and levels of scale.

Others said regulation presents an opportunity for those in the peer-to-peer lending space.

“Those with strong FCA relationships (e.g. ISA approvals), and at scale can become ring-fenced, which raises barriers to entry and introduces government downside protection,” added Goldman's note.