Foreign-exchange broker FXCM will stop trading a number of currencies later this week to avoid volatility caused by possible future intervention by governments in currency markets, according to a person familiar with the matter.

The New York-based broker lost millions of dollars following the sharp currency swings resulting from the Swiss National Bank 's decision to remove its cap on the value of the franc on Jan. 15. It has begun notifying clients that on Feb. 20 it will remove a number of currencies, including the Hong Kong dollar and Danish krone, from its platform, the person said.