As was recently posted in the news, FXCM will stop supporting US client accounts and they will likely be transferred over to GAIN Capital – http://www.financemagnates.com/forex/brokers/breaking-fxcm-sell-us-accounts-gain-capital/.
Currently TradingView has a technical integration with FXCM for trading, but does not yet have one with Gain. We are working on enabling such a technical connection as early as possible. We will post continuous updates in the blog regarding the availability.
Feel free to ask any questions through support@tradingview.com.