“OANDA states regulatory considerations contributed toward its decision to discontinue precious metals trading, citing changes in US laws which stipulate that traders located in the United States traders will no longer be able to trade precious metals with margin or leverage, a total contrast to the landscape which currently is evolving outside the United States, whereby institutional and retail electronic trading firms alike are considering the consolidation of FX and precious metals due to their compatibility within a single business unit and trading platform. US residents are restricted solely to FX trading via the fxTrade platform, as US laws also prohibit the trading of CFDs.”
http://leaprate.com/2014/09/oanda-halts-margin-trading-on-precious-metals-in-the-united-states/