The vast customer data troves of the Big Tech firms challenges traditional approaches to competition policy and the maintenance of financial stability, according to the Bank for International Settlements.

The entry of large technology firms such as Alibaba, Amazon, Facebook, Google and Tencent into financial services, including payments, savings and credit, could make the sector more efficient and increase access to these services, but also introduces new risks, says the central bankers' bank.

Some are old issues of financial stability and consumer protection in new settings, but a new element is Big Techs' access to data from their existing platforms. This could spark "rapid change in the financial system through the emergence of dominant players that could ultimately reduce competition".

The issues raised go beyond traditional financial risks, according to the BIS. Tackling these requires striking a balance between financial stability, competition and data protection.

As Big Techs' move into financial services accelerates - expanding beyond regulatory perimeters and geographical borders - policymakers will need institutional mechanisms to help them work and learn together, says says Hyun Song Shin, cconomic adviser and head of research at the BIS

"The aim should be to respond to Big Techs' entry into financial services so as to benefit from the gains while limiting the risks," he says. "Public policy needs to build on a more comprehensive approach that draws on financial regulation, competition policy and data privacy regulation."