Bitcoin and cryptocurrencies present several challenges for investors and banks, including their use by criminals, according to Anne Boden, chief executive of Starling Bank Ltd.

“People are being scammed and the proceeds normally go into crypto wallets,” Boden said in a virtual interview with Bloomberg UK. The assets are also in a valuation bubble and aren’t sustainable in the long term because of the environmental issues they will cause, she said.

Starling last month raised new funds in a round valuing the business at more than £2.5 billion ($3.1 billion), in a rare example of a European fintech achieving a value that was double the level of its previous round. All of its existing investors participated, including early backer Harald McPike and a unit of Goldman Sachs Group Inc.

The bank could list in London at the end of next year, Boden said. The London market is “harder (than the US) on technology companies and loss-making companies,” but Starling is profitable, she said.

Starling’s future growth will partly come from selling its bespoke technology platform, Engine by Starling, to other businesses that want to offer banking services, Boden believes.

“In four to five years’ time, I think we’ll be a global technology company that owns a bank in the UK,” Boden said.

“Big banks around the world have a huge problem, it’s not a problem of innovation, it’s a problem of cost base, and being stuck on technology that’s gone past its sell-by date,” Boden said.

Starling has fielded inbound queries from other banks, including in the US, about using its technology. Starling would package it as a software service, with users needing to source a banking license from another party, she said.

Boden set up Starling in 2014. The bank has 2.9 million customer accounts, including 450,000 belonging to small and medium-sized businesses. Given its market share, it can no longer be called a challenger bank in the UK, she said.

Starling is not for sale, Boden said when asked about takeover approaches from larger rivals. The bank is looking at acquisitions itself, including potentially adding lending platforms.

Boden, a frequent user of Twitter who was speaking via Twitter Spaces, said about billionaire Elon Musk’s acquisition of the streaming platform: “We must question whether the richest man in the world and his ownership of Twitter is something the world really wants but that is for another day.”

–By Ruth David (Bloomberg Mercury)