Citigroup Inc., the world’s biggest currencies dealer, lost more than $150 million after the Swiss central bank decided to let the franc trade freely against the euro, Bloomberg reported. The losses took place on Citi’s trading desks and are not tied to its relationships with currency trading services provider FXCM Inc. and other retail trading platforms, Bloomberg said, citing a person briefed on the matter. The Swiss National Bank shocked financial markets on Thursday by scrapping a 3-year-old cap on the franc, sending the currency soaring against the euro and stocks plunging on fears for the export-reliant Swiss economy.