Switzerland's central bank said Friday it lost a record 50 billion francs ($51 billion, 47 billion euros) in the first half of 2015, due mainly to the hefty depreciation of its foreign currency holdings.

The Swiss National Bank had been holding down the value of the franc for more than three years, but suddenly announced on January 15 that it was abandoning the minimum rate of 1.20 francs to a euro.

The decision to scrap the limit sent the franc -- a refuge currency -- soaring in value against major currencies and unleashed turbulence on global markets.

"The subsequent appreciation of the Swiss franc led to exchange rate-related losses on all investment currencies. For the first half of 2015, these amounted to a total of CHF 52.2 billion," said the SNB.

The central bank however made some money from interest income, which reached 3.5 billion francs, as well as from dividends amounting to 1.2 billion francs.

Despite the massive loss, the SNB said strong fluctuations are expected in its financial results which depend largely on developments in the gold, foreign exchange and capital markets.

"Only provisional conclusions are possible as regards the annual result," added the bank.