CORRECTION (Nov. 20, 10:02 UTC): Corrects headline and story to say service is available for clients with accounts in Switzerland. An earlier version said the service was for Swiss clients.

Santander Private Banking International, part of Spanish financial services giant Banco Santander, is offering high-net-worth clients with Swiss accounts trading and investing in the major cryptocurrencies bitcoin (BTC) and ether (ETH), according to an internal announcement seen by CoinDesk.

Over the next several months, Santander will offer additional cryptocurrencies that meet the bank’s screening criteria, the announcement said.

Santander said the service is provided only upon client request through relationship managers, and the assets are held in a regulated custody model in which the bank stores the private cryptographic keys in a secure environment.

This is a bold move, given that most big banks prefer to be twiddling around with tokenization and tend to avoid exposure to open-access blockchains and the cryptocurrencies that run on them.

Banco Santander is more than 160 years old and has 166 million customers. The private bank caters to 210,000 wealthy clients, with assets and deposits accounting for about $315 billion.

“The Swiss regulation related to digital assets is one of the first and most advanced in the world, since it provides clarity and a comprehensive regulatory environment for our clients,” said John Whelan, head of crypto and digital assets at Santander, in an email. “As holding of crypto as an alternative asset class continues to expand, we expect that our clients prefer to rely on their existing financial institutions to be responsible for their assets.”