The dollar has been weakening since the start of the year, and is now in the process of testing some important chart support. The weekly bars in the chart below show the U.S. Dollar Index ($USD) testing a support line drawn under 2012-2013 lows. A decisive close below that trendline would represent a technical breakdown in the greenback. There would be at least two possible side effects if that were to happen. One would be a boost in commodity prices (like gold) which generally rise when the dollar falls.