While big banks can absorb losses on markets, for some smaller firms, the volatility in the franc proved too much.
Alpari, the London-based brokerage firm that sponsors the shirt of English Premier League football club West Ham United, said it had to shut down its business.
The firm said the majority of its clients sustained losses which exceeded their account equity. "Where a client cannot cover this loss, it is passed on to us," it said. "This has forced Alpari to confirm today that it has entered into insolvency."
FXCM, a New York-based currency broker, said it was getting a US$300 million rescue loan from financial firm Leucadia National. It had warned that it could be in breach of regulatory capital requirements after a US$225 million loss.
FXCM is one of the largest retail currency brokers in the world and its shares were suspended on the New York Stock Exchange after its announcement.
Citigroup is the largest prime broker to FXCM, with potentially tens of millions of dollars of credit extended to the struggling company.
The Financial Times reports that overall, Citi has incurred a US$150 million loss as a result of the Swiss franc's appreciation, on a par with losses at Deutsche Bank. Barclays had lost close to US$50 million, traders said. Another retail trading platform, Connecticut-based Interactive Brokers, revealed it lost US$120 million although that was only 2.5 per cent of its net worth.
And two Greek banks are in trouble, partly as a result of market gyrations after the Swiss moves.
Officials at Greece's central bank say two of the country's lenders are seeking emergency assistance after international market turmoil and amid financial uncertainty in Greece ahead of a general election on January 25.
In Auckland, Global Brokers NZ., a small currency trading house, was also caught out.
On Friday, director David Johnson announced on the website of affiliate Excel Markets that it could no longer meet the regulatory minimum to continue business.
The Financial Markets Authority is seeking assurances that the client funds have been protected and segregated as the the company had stated.
Swiss National Bank president Thomas Jordan defended his country's move saying it was better to be criticised than risk credibility.
"If the SNB had continued with its policy, it risked losing control of long-term monetary policy."
The primary reason behind the Swiss National Bank's decision to stop keeping a lid on the franc against the euro is that the European Central Bank is widely tipped to back a big stimulus programme. That will put more euros in circulation, further diluting their value.
The Swiss franc's move is the latest in a string of developments that have threatened the world economy.
- Agencies
